Spellcasting- When you reach 3rd level, you augment your martial prowess with the ability to cast spells.

Cantrips- The fighter may learn 3 cantrips from the wizard and/or artificer spell list. The fighter can learn additional cantrips when you gain levels in this class. Can learn an additional cantrip at levels 5, 11, and 17.

Spellcasting Ability- Intelligence is your spellcasting ability for your wizard spells, since you learn your spells through study and memorization. You use your Intelligence whenever a spell refers to your spellcasting ability. In addition, you use your Intelligence modifier when setting the saving throw DC for a wizard spell you cast and when making an attack roll with one.

Spell save DC = 8 + your proficiency bonus + your Intelligence modifier

Spell attack modifier = your proficiency bonus + your Intelligence modifier

3rd Lv. Spell Mark/Cantrip Caster

Gain proficiency in Arcana.

Cantrip Caster- The fighter is able to cast a cantrip spell that has a casting time of one action and that is unable to deal any damage as a bonus action.

Spell Mark- Your fighter is able to place a glyph or sigil of magic on an enemy, ally, or themselves to enhance themselves and others while bringing harm to their foes. You have a number of spell marks equal to your proficiency bonus and you regain all spent spell mark's after a short/long rest. A target for your spell mark must be within 30 feet of the fighter and you must have line of sight on them to place the mark. At 3rd level you can only have one spell mark activated at any given time.  You use a bonus action to place a spell mark on a target and these spell marks have the following effects depending on if it is placed on yourself, an ally, or enemy. Expending the spell mark causes it to disappear and any passive effects are removed as well. A spell mark dissipates after one minute, if not consumed, or if it falls under an effect such as dispel magic.

When placed on yourself, as long as the mark remains on you, you have advantage on any Wisdom (Perception) ability checks and you can add your intelligence modifier to your rolls if what you are trying to perceive is magical in nature . On a failed ability check or saving throw, you can use your reaction to expand your spell mark in order to add your intelligence modifier to the rolled number in order to potentially turn that failure into a success. You must do so after you have rolled the die but before your DM determines if it was a success or failure. 

When placed on an ally, as long as the mark remains on them, they gain advantage on any ability checks they are proficient with. When an ally is inflicted with a status condition such as being charmed, frightened, or stunned then you may use your bonus action on your turn to expend the mark from them in order to remove one status condition from them.

When placed on an enemy, as long as the mark remains on them, they are unable to receive any benefits from features or spells such as being hidden, or invisible against you. When you hit a target that is spell marked with an attack, you may expend your mark in order to deal an additional 2d6 as force damage.  

7th Lv. Cantrip Extra Attack/Spell Mark Slots

When you take the attack action, you are able to replace one of your extra attacks with a damage dealing cantrip but it can only be cast as a 5th level cantrip. At level 13 you are able to replace 2 attacks with a damage dealing cantrip. 

You are able to use your unused spell marks as spell slots for your fighter's known spells. You consume unused spell marks equal to the spell slot level in order to cast the spell (example, consume one spell mark to cast a level 1 spell, consume 2 spell marks to cast a level 2 spell). You may also upcast any known fighter spell by expanding additional spell marks to cast the spell (expend 2 spell marks to cast a level 1 spell as a level 2 spell) you can only upcast a spell to the highest level of your current highest known fighter spell. You are only able to use your spell marks for any spells known by your fighter and you can ignore any somatic components needed for a spell cast in this way as well as any material components as long as the materials do not require any items with any monetary value. Additionally you are able to cast any spell with a casting time of one action and is a non-damage dealing spell cast with your spell mark(s) as a bonus action.

At 7th level you learn 3 level 1 spells and 2 level 2 spells from the wizard and/or artificer spell table and you learn additional spells at the following levels. One level 1 and level 2 spell at 10th level, 1 level 3 spell at level 15, and one level 3 and 4 level spell at 18th level. Additionally whenever you take a long rest you may replace a number of known spells equal to your intelligence modifier with other spells of the same level of the swapped spells from the wizard and/or artificer spell table.

10th Lv. Empowered Spell Mark/Spell Drain

Empowered Spell Mark-You are now able to have 2 spell marks active at any given time. As a bonus action on your turn you may teleport to an unoccupied space within 5 feet of an ally or enemy within 30 feet of you that has a spell mark applied to them.  

Spell Drain- When an enemy that you can see within 60 feet of you casts a spell you can have that enemy make a saving throw based upon either their wisdom, charisma, or intelligence against your fighter's spell save DC. Then enemy can choose which ability score to use but it can not be the ability score they use for their spellcasting (example: if the enemy casts spell using wisdom as their spell attack bonus and spell save DC then they can not choose to use their wisdom score to try and beat your fighter's spell save DC). On a failed saving throw, the spell fails and has no effect, the spell slot used to cast it is wasted and your fighter gains a spent spell mark back. You can only use this ability a number of times equal to half your proficiency bonus (rounded down) before needing to take a long rest to regain all uses of this feature back.

15th Lv. Cantrip/Spell Mark Improvement

You may apply your intelligence modifier to the damage of any cantrip spell cast as part of your extra attack. At 15th level your spell mark gains the following features in addition to the other previous listed features.

When applied to an ally, as long as the spell mark remains on your ally, if both you and your ally with the spell mark are within 5 feet of an enemy and neither one of you are incapacitated than both of you have advantage on your melee attacks against that enemy. If an ally with this spell mark is dropped to 0 hit points and are not killed outright, you may use your bonus action on your turn to expand your spell mark on them to have your ally regain hit points equal to your fighter's level + your intelligence modifier.

When applied to yourself, as long as the spell mark remains on yourself you have advantage on spell saving throws and saving throws to escape a spell effect. As a reaction when you are subjected to an effect that deals area of effect damage, you may expend your spell mark to have any damage you receive on a failed saving throw be halved and take no damage from any successful saving throw. 

When applied to an enemy, as long as the spell mark remains on an enemy, you deal an additional 1d6 as force damage whenever you hit that enemy with an attack. As a bonus action on your turn, you may expend your spell mark on an enemy to have them make an intelligence saving throw against your fighter's spell save DC and on a failed save become stuned until the start of your next turn.

18th Lv. Cantrip/Spell Master

You may replace two of your known cantrips with another 2 from any other class. These cantrips are treated as wizard and/or artificer spells and use intelligence for their spellcasting attack and save DC. Whenever you use a cantrip to perform an extra attack, once per attack action, for one of those attack damage roll only, on a hit you may roll damage dice for one of your cantrip spell attacks as if you had cast it at a full 17th level cantrip spell. 

You may choose one of your level 1 and level 2 spell spells that your fighter knows. You are now able to cast those two spells at their lowest level as if they were a cantrip spell without the use of a spell mark.