School of Necrosummoner

Have you ever wanted to talk to your friend who died in a horrible crash, but not limited to a 24-hour animate dead spell, welcome to the necrosummoner. We believe in recycling and reusing those we do and don't know even in death. 

Undead Familiar

Beginning with this school at 2nd level you can cast animate dead once per day without consuming a spellslot. Casting animate dead will create an undead familiar.
You gain the service of an undead familiar.
Your familiar acts independently of you, but it always obeys your commands. In combat, it rolls its own initiative and acts on its own turn. 
When the familiar drops to 0 hit points, it crumples to the ground. It reappears after you cast this spell again
While your familiar is within 100 feet of you as an action, you can see through your familiar’s eyes and hear what it hears until the start of your next turn. During this time, you are deaf and blind with regard to your own senses.
You can’t have more than one familiar at a time. If you cast animate dead while you already have a familiar any other undead will be under the usual effects, restrictions, and bonus of the normal animate dead spell.
Finally, when you cast a spell with a range of touch, your familiar can deliver the spell as if it had cast the spell. Your familiar must be within 100 feet of you, and it must use its reaction to deliver the spell when you cast it. If the spell requires an attack roll, you use your attack modifier for the roll.

Undead Thralls

 Whenever you create an undead using a necromancy spell, it has additional benefits:

• The creature’s hit point maximum is increased by an amount equal to your wizard level.
• The creature adds your proficiency bonus to its weapon damage rolls.

Your undead familiar can now cast ranged spells as if you had cast them. 

Greater Undead

Starting at this level as your once-a-day animate dead and a spell slot of your choice you can reanimate any creature with a CR rating equal to your spell level. Once this creature has been reduced to 0 hit points it can no longer be revived. The creature is loyal to you requiring no concentration on the spell. 

The creature rolls its own initiative and can cast one of your spells as its reaction. 

You are now resistant to necrotic damage.

Behold Undeath

Any summoned undead does not require a recasting of animate undead. This applies to all undead and not just your familiar. In addition, should you choose to use your once-per-day ability plus a spell slot, summon any number of undead where their CR is equal to your spell slot. These undead will also not suffer the effects of decay and do not require a recasting of undead. 

Due to your time spent around the undead, you are now immune to necrotic damage.