Your studies have led you to unbind the formulas of the spells you cast. You have managed to unfetter the arcane power contained within them with the negative energy in the world around you. As you cast spells, you can call on negative energy to power your spells and make them more powerful.

The taint of negative energy shows in every spell you cast. Shimmering sheets of dark power cascade over you and cause affects all around you. The flames of your spells burn with a dark Necromantic tinge and your cold spells carry the chill of  the grave. 

• At 3rd level, you begin to adapt to energies that would destroy lesser men: Savant Path- Archivist of Ruin (2 Spells) + Undead Familiar + Corruption + Terrifying Mein.
• At 6th level, you gain command of the undead and the forces that govern them. Those powers start to sustain you as well: Necromantic Control + Arcane Restoration.
• At 10th level, your entire physiology begins to change - stronger in many ways but weaker in others: Desecrated Form.
• At 14th level, You are capable of containing the negative energy more effectively and containing to empower your spells further: Devourer + Iron Vessel.

Construct Undead Familiar

Wizard 3rd Level - Arcane Desecrator

Construct Undead Familiar
Starting at 2nd level, you can assemble an undead familiar through necromantic craft.

Create the Familiar. You can perform a special ritual that takes 1 hour and requires 10 gp of grave-dust, bone, thread, and reagents (consumed). When you complete the ritual, you create an undead familiar that takes the form of a Tiny beast (bat, cat, rat, raven, spider, toad, weasel, or another Tiny beast approved by the DM). Your familiar is an undead creature instead of a beast.

If your familiar is reduced to 0 hit points, it is destroyed. You can create it again by performing the ritual.

Swift Dismissal. As a bonus action, you can dismiss your familiar into a pocket space or cause it to reappear in an unoccupied space within 30 feet of you.

Commanded Attack. Your familiar can take the Attack action, but only when you use a bonus action on your turn to command it to attack. If you don’t command it, it can take other actions normally (Dodge, Dash, Help, Hide, etc.).

Conduit Casting. While your familiar is within 60 feet of you, when you cast a wizard spell of 1st level or higher with a range other than Self, you can choose your familiar’s space as the spell’s point of origin. You can do this a number of times equal to your proficiency bonus per long rest.

Bonded Vitality. When your familiar takes damage, you can use your reaction to take that damage instead (after resistances/immunities are applied). If you do, your familiar takes no damage from that instance.

Compatibility Note. If you also learn or gain the find familiar spell from another source, you may still cast it, but any familiar you summon is undead and uses the rules in this feature (DM adjudicates edge cases).

Level 3: Corruption

Wizard 3rd Level Arcane Desecrator

Starting at 3rd level, you are able to draw negative energy out of the environment to drive and fuel your spells. As you do, the negative energy bubbles up through the earth and flows into you in streams of dark energy. This kills all plant life and small wildlife within 5 feet per level of the spell being corrupted. If there is no life in the area, the earth Within the damage radius is corrupted for and nothing will grow in it for a year.

 

Activate. As a bonus action, you enter a corrupted state that lasts for 1d6 rounds. You can do this a number of times equal to your Intelligence modifier (minimum 1), and you regain all uses when you finish a long rest.

Corrupt a Spell. While Corruption is active, when you cast a wizard spell of 1st level or higher, you can apply one of the following benefits to that spell (choose each time you cast):

• Grim Precision: Add your proficiency bonus to one spell attack roll you make as part of the spell.

• Necrotic Surge: Add your proficiency bonus as necrotic damage to one damage roll of the spell.

• Oppressive Weave: Increase the spell’s saving throw DC by +1 for this casting (+2 starting at wizard level 10).

Negative Environmental Drain: The area around the Arcane Desecrator becomes decayed, as they grow in power, the devastation gets worse at a radius of 5 feet per level, up to 70 feet. 

Back Lash -- Epidemic Surge (6th Level). Starting at 6th level, the Corrupted Area becomes actively lethal. When you corrupt a spell, each creature of your choice other than you in the Corrupted Area must make a Constitution saving throw against your spell save DC, taking necrotic damage equal to your proficiency bonus on a failed save, or half as much on a success. You are immune to this damage.

Negative Energy Mastery (10th Level). Starting at 10th level, when you corrupt a spell you can designate a number of creatures you can see within the Corrupted Area up to your proficiency bonus. The chosen creatures are immune to any damage caused by your Corrupted Area until the start of your next turn, and each chosen creature gains temporary hit points equal to your proficiency bonus (a creature can gain these temporary hit points only once per Corruption activation).

Containment Lattice (14th Level). When you corrupt a spell, you can impose a containment lattice on the Corrupted Area until the start of your next turn. The area creates a Slow Movement zone for hostile creatures. The first time each hostile creature starts its turn in the area, it must succeed on a Strength saving throw against your spell save DC or have its speed reduced to 0 until the start of its next turn. You are immune to this effect.

Once per Corruption activation.

Level 3: Terrifying Mein

Terrifying Mein
Starting at 3rd level, the negative energy you channel clings to you like a stormfront, and creatures can sense something wrong when you work magic.

You gain proficiency in the Intimidation skill. If you already have proficiency, you instead gain expertise in Intimidation (your proficiency bonus is doubled for checks you make with it).

Dread Display. While your Corruption is active, when you cast a wizard spell of 1st level or higher, you can force one creature of your choice that can see you within 30 feet to make a Wisdom saving throw against your spell save DC (no action required; once per turn).

• On a failure: the creature is frightened of you until the end of your next turn.

• On a success: the creature is immune to your Dread Display for 24 hours.

A creature that is immune to being frightened automatically succeeds on this saving throw.

Level 3: Archivist of Ruin

Wizard Level 3 Arcane Desecrator - Savant Path

Archivist of Ruin
Beginning when you adopt this tradition, you have learned to break arcane patterns apart and reassemble them through negative energy.

Ruinous Transcription. The gold and time you must spend to copy a wizard spell into your spellbook is halved if the spell is a Necromancy spell, deals necrotic damage, or creates or summons an undead creature. The DM determines whether a spell qualifies.

Deconstruct the Weave. When you make an Intelligence (Arcana) check to identify, analyze, or counteract a spell or magical effect you can see (including checks related to counterspell, dispel magic, glyphs, wards, and similar arcane workings), you can add 1d4 to the roll. You can do so a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

Level 6: Necromantic Control

At 6th level, you are able to control undead. When you create undead by casting any spell, you are able to maintain control over these created undead. You may control a number of  undead equal to your Proficiency Bonus plus your wizard levels. The Strength of the undead creatures you control are  equal to Hit die plus PB minus one of the caster.

Unstable Overbinding. When you create undead with a wizard spell, you can choose to exceed your control limit until the end of your next long rest. If you do, immediately after the spell is cast you must make an Intelligence (Arcana) check with a DC equal to 10 + the number of undead you control beyond your limit.

• On a success: you maintain control until the end of your next long rest (at which point any undead beyond your normal limit become uncontrolled unless you dismiss some).

• On a failure: the binding slips. A number of undead equal to the amount you are over the limit become uncontrolled immediately.

• On a failure by 5 or more: the uncontrolled undead become hostile to you and your allies for 1 minute (DM controls them), after which they behave according to their nature.

Caution is advised. Uncontrolled undead are not commanded by you and may attack creatures nearby, flee, or cause harm at the DM’s discretion.

When you create new undead creatures, you must choose which ones you maintain control of. The rest become free-roaming undead and act accordingly. Caution is advised.

Level 6: Arcane Restoration

Arcane Restoration
Starting at 6th level, you can metabolize the negative energy you channel into restoration—at a cost.

As an action, you expend one use of your Corruption and choose one of the following effects:

Siphon Spell. Regain one expended spell slot of a level up to ⌊your wizard level / 5⌋ (minimum 1). You can’t regain a slot higher than 4th level with this feature.

• Wizard level 6–9: 1st

• 10–14: 2nd

• 15–19: 3rd

• 20: 4th

Purge the Taint. You cast lesser restoration on yourself, requiring no components.

Backlash. After you use Arcane Restoration, make a Constitution saving throw against a DC of 10 + the level of the spell slot regained (or DC 12 if you used Purge the Taint).

 

• On a failure, you take necrotic damage equal to your proficiency bonus and gain 1 Craving (as defined by Desecrated Form).

• On a success, no backlash occurs.

 

Level 10: Desecrated Form

Desecrated Form
Starting at 10th level, repeated exposure to negative energy warps your body into a hardened, hungry vessel.

Desiccated Flesh. While you aren’t wearing armor, your AC equals 13 + your Dexterity modifier.

Hardened Vitality. Your hit point maximum increases by 10, and it increases by 1 whenever you gain a wizard level.

Craving

You develop an addiction to negative energy. You have a Craving score that ranges from 0 to 3.

Gaining Craving.

• If you finish a long rest and you have not activated Corruption since your previous long rest, your Craving increases by 1 (maximum 3).

• Some features (such as Corruption Backlash or Arcane Restoration Backlash) may also cause you to gain 1 Craving.

Effects of Craving.

• Craving 1 — Edges of Hunger: You have disadvantage on Persuasion and Insight checks.

• Craving 2 — Shaking Focus: You have disadvantage on Constitution saving throws you make to maintain concentration on a spell.

• Craving 3 — Withdrawal: You are poisoned. In addition, when you finish a long rest while at Craving 3, you gain 1 level of exhaustion.

Sating the Hunger. When you activate Corruption, your Craving becomes 0 at the end of that Corruption.

Level 14: Devourer

Devourer
Starting at 14th level, your corrupted magic can feed on the living and leave only hunger behind.

Devouring Strike. When you corrupt a spell using your Corruption feature, you may choose one creature that is affected by the spell (a target of the spell, or a creature within the spell’s area). That creature must not be undead or a construct, and it must make a Constitution saving throw against your spell save DC.

• Failure: The creature takes necrotic damage equal to 1d6 × the spell’s level.

• Success: The creature takes half as much necrotic damage.

Rising Death. If this damage reduces the creature to 0 hit points, it rises as a zombie (use the Zombie stat block) after 1d4 rounds, acting on the end of your turn when it rises.

Control. The zombie is under your control for 24 hours, after which it becomes uncontrolled unless you maintain control of it through your Necromantic Control feature. This zombie counts against your control limit. If you are already at your control limit when it rises, it becomes uncontrolled immediately. - You also gain 1 Craving. 

Limit. You can use Devouring Strike once per turn. You fortunately, can only gain one craving per use of Devouring Strike.

Frenzied Rising. If the creature fails its saving throw against your Devouring Strike by 5 or more, the negative energy surges out of your control. When the creature rises as a zombie, it rises in a frenzy: it is uncontrolled and hostile until the end of your next turn (the DM controls it).
At the end of your next turn, you can attempt to seize control as a bonus action by making an Intelligence (Arcana) check against a DC of 10 + the spell’s level. On a success, the zombie becomes controlled by you (still counts against your control limit). On a failure, it remains uncontrolled.

Level 14: Iron Vessel: I Know What I’m Doing

Iron Vessel: I Know What I’m Doing
Starting at 14th level, you’ve learned to brace your body and mind against the worst surges of negative energy—because you’ve made every mistake you’re ever going to make.

Contained Corruption. While your Corruption is active, you gain resistance to necrotic damage and poison damage, and you have advantage on saving throws to avoid or end the poisoned condition.

Measured Intake. Once each time you activate Corruption, you can choose to ignore one of the following effects that would apply to you:

• the necrotic damage from a Backlash (such as from Corruption ending or Arcane Restoration), or

• gaining 1 Craving from a subclass feature (such as Backlash or a Frenzied Rising “oopsy daisy” result).

You must choose to use this benefit when the effect would occur.

“I’ve studied this, I’ve lived it, I can hold it.”