In Blood Omen 2, he awakened from a centuries long coma and almost all of his previous powers had disappeared, but it was said that he would eventually recover them. He also gained a few new abilities in the meanwhile.
-Mist form is again used, although it is said that some kind of magic sensitive knights could detect him in this form and he cannot feed while using it.
-Fury. It allows him to make one powerful and "unblockable" attack.
-Jump. He can jump "massive" distances. I will try to find some quantification.
-Charm. He gained this one from a vampire that could use it to control most minds and read those particularly strong that he could not control (like Kain's). Kain was able to use it to control some humans, but it is unknown whether he developed it enough to read minds.
-Berserk. Increased speed and allows to make several powerful and "unblockable" attacks.
-Telekinesis. His natural TK powers were increased once he gained this. Again, there is no clear quantification, although it is said that a single hit is enough to kill some humans and that Kain had enough accuracy to make shattered statues reform.
-Inmolate. His most powerful attack in that game, also considered "unblockable". It incinerated any enemy (exception made of the final boss). For quantification purposes, it can be mentioned that the vampire that Kain gained it from used it to shatter stone statues.
Finally, in Defiance, he used several spells gained from the Reaver in its different incarnations.
-Flame Reaver. Nearby enemies attack each other/fire damage. It also granted Kain pyrokinetic powers.
-Dimension Reaver. All nearby enemies are damaged as the attacked enemy. Allows Kain to make short teleport jumps to attack nearby enemies before returning to his original position.
-Time Reaver. The enemies it hits are slowed. All nearby enemies are slowed.
-Lightning Reaver. All nearby enemies are hit by lightning.
-Soul Reaver. At this point, the Reaver becomes the Soul Reaver as seen in Blood Omen and SR1. Relevant quote.
"Time fades even legend, and the origin of Soul Reaver has been lost long ago. But its purpose remains - to feed on the souls of any creature it strikes. Kindred, this blade and I."
The Soul Reaver could explode most enemies with one hit. As the Soul Reaver was a two-handed weapon, Kain could not cast spells or use items while he was equipped with it. The sword required an expenditure of Kain's magical energy to maintain this level of power, and it drained his magic reserves by an amount equal to the health (hit points) of each creature it killed. If Kain had no magic energy left, the Soul Reaver was only as effective as his Iron Sword.
