There is not a casual way to complete the necromancer epic, sorry to burst everyone's bubble. Realistically if you are not a hardcore player this item is out of reach.
The best bet is to get VP keyed (HUGE time sink for a casual player in its own right) and get
https://wiki.project1999.com/Shissar_Seance_Staff - even so you need to be in one of the top 3 guilds (I've no idea who competes in VP these days)
Most agree its better than the Epic anyways. However the chances of getting this staff are lightyears more feasible than getting Inny, CT, and Sky loot as a casual