Couple Necro Ideas,

ability to drag multiple non elite mobs behind you with chains to reposition them (or a 20-30 meter pull for 4 normal enemies randomly selected furthest away, shoots chains from back and pulls them to you)

bone packpack, stores corpses, maybe when it uses scythe it reaches back into the backpack grabs a bone and bone morphs into a scythe as it swings

maybe you get 10-20 corpses in backpack you can store, walk over corpses in game to refill? can cast corpse using abilities directly attached to enemies

scythe throw instead of shield throw to reap multiple enemies in as an aoe boomerang pull

maybe when you kill enemies you can have an ability to conjure the corpses into temporary minions (although i dont really like the minion thing personally, too much clutter especially if there is alot)

make colo the tank ultimate, maybe provides vuln + defense or something with no damage, dps ultimate could summon 10 skeletons that blast like old blast bones on the enemy, for however many enemies are killed generate ult back, remove res ultimate for something else, personally think its bad game design to plan abilities off of other players being dead, was a necro main for years and refused to use it to carry people.

scythe heal, when your scythe swings it sends a reap aoe heal proceeding forward across 20 meters and heals anyone in the way

remove venom skull/flame skull, make the spammable either a sick blastbones or maybe a range scythe you throw

honestly prob remove frost/shock damage, focus strictly on disease, or even necrotic damage.

another though is focusing on a playstyle like corpsebuster, the explosions for massive damage is absolutely sick, i used to use plaguebreak before it was nerfed into the ground and that was the most fun I ever had in all of my time playing necromancer.

scythe style beam, continually swings scythe back and forth 15 meter range for 3-5 seconds