Hello guys!
To Get Abbadon!
1.go to the planar and do any tomb
2.in planar u must capture a skeleton
3.go to arcanum grounds
4.kill all enemies but don't destroy artifact
5.give the skeleton a piece of artifact and the skeleton will become green aura
6.now,cut his legs
7.kill the skeleton
8.the skeleton now we see only soul(not invincible)
9.give him a black axe
10.teach him fly!
11.Give him grey armor and green horns

There guys! U got Abaddon! Happy Farming!