You see Twisterror.
Notes
To summon this miniboss you must use 10 Spellreaper Staff Totem on the Sacrificial Altar found here.
Abilities
Unknown.
Damage Taken From Elements
Physical 
Death
Holy
Ice
Fire
Energy
Earth
Drown
Location
Azzilon -2 (here)
Behaviour
Twisterror attacks in melee range. Twisterror never retreats.