To easily take down those 3 abominations creatures in the small room, just get lvl 1 firewall and the problem can be solve easily. After that stitch Sassan disappear, there is a very short duration before the creature will be summon out. Position your char near the spot where the abominations creature will pop out and use your firewall. You can see them die within a second or 2 if you pick the location correctly, where the creatures spawn on the fire line of your firewall
And regarding nebarius creature, there a red ore mine across the river where the fortune teller is. The creature is inside the mine. Slay it and get the crystal skull, and nebarius will construct necromantic creatures for you.
