Uldyssian is the central character in the sin war trilogy and part of the Diablo lore, a farmer who lost most of his family. He is the pawn chosen to begin a terrible shift in the world of Sanctuary

Uldyssian has Nephilim (Demon+angel=Nephilim) ancestry within him and has some of their powers, his powers can do almost anything from changing weather, causing people to explode, Shields or simply creating a simple ball of light to see through the dark with, he also has teleportation it seems and Teleporation of others among amping his strength and healing powers, his pwoers are based on his will, the more desperate and angry he gets the more powerful his abilites are but he is said to be able to do almost anything within his will, he can aso transmute objects.

Uldyssian tremendous TK and will powers

"When Uldyssian returns to his followers, he displays astonishing power by keeping the entire temple from collapsing until his followers can escape"

Altering the structure of the world stone, dont know what this would come under, transformation, transmution or something else *shrug*, alters the structuers of things anyway

"the worldstone. There, Uldyssian tries to use it to give his followers more power, but ends up altering its structure"

makes people combust and their bodies split with a whim.

"tears spread across his body, as if invisible swords slashed at him from every direction, blood seeped even from beneath breastplates...."

hes quite a good character, not directly "in" a game, but hes part of the lore and his story originates from Diablo as does his world, he is part of it all.