Lich is now a race evolution for Necromancers, with it's own racial talent tree

game/modules/tome/data/birth/worlds.lua

game/modules/tome/data/talents/uber/mag.lua

game/modules/tome/data/talents/undeads/lich.lua

game/modules/tome/data/talents/undeads/undeads.lua

game/modules/tome/data/timed_effects/magical.lua

game/modules/tome/data/timed_effects/other.lua

game/modules/tome/dialogs/DeathDialog.lua

game/modules/tome/dialogs/debug/PlotTalent.lua