I'm building up a character concept based around abusing the Warlock's access to Animate Dead from [Class Feature Variants](https://dnd.wizards.com/articles/unearthed-arcana/class-feature-variants
It's tempting to go Hexblade, pact of the blade and pick up heavy armour also from Eldritch Armor.
The reason Elf is elected as essential is for trance, 4 hours sleep, 4 one hour short rests, is (at level 5) is 8 hours and 6 minutes, if you include the 2 minutes per first three rests to cast animate dead twice and maintain control over 24 zombies and then also rest to restore the spell slots for the day. Alternatively you could control 32 zombies, and rely on your auto attacks and cantrips.
Effectively building a fighter with cantrips and 25 attack rolls.
I know this could be multiclassed easily into oathbreaker, or just continue straight warlock for a bigger horde, I'd personally keep going warlock for fun things like Magic Jar while you can have your zombies carry you in a litter and protect your form, and eventually trading up to Create Undead (although that's still a long rest, so less abusable).
Essentially it's a minion master build, absolute nightmare for the DM if the player isn't very prepared I know... but I really enjoy the idea of either a sentient weapon or an improved familiar, and then creating a homunculous, some intelligent undead and a retinue of zombies... plus making the character's own body mostly superfluous with things like magic jar and clone. Clone needs some DM fiat as it isn't on the list, but for a necromancer researching lichdom... it makes sense to try to get access.
Patron wise, undying makes the most sense... even if your patron is simply a Liches diary you're translating over time... it feels weaker than Hexblade though.
Hexblade makes sense if the weapon is imparting this sort of knowledge.
Open to suggestions, but yeah, mostly just want all the pets... like animate dead in the morning, then danse macabre or animate objects during combat.