Urost the Soulcage is a Void legendary from the Undead Hordes faction. Urost was added to Raid Shadow Legends in patch 3.0 as a fragment collector reward for beating the secret rooms on Hard Doom Tower. Urost has a monsterous kit applying poisons passively when hit, increasing his own HP and decreasing enemy HP and applying strengthen and ally protect buffs to his team. Urost also has an AOE ability that improves based on the number of poisons on the enemy targets. When paired with Rian the Conjurer he also has enhanced abilities if revived by him!
Overall a great legendary that will be viable in any content but strongest when able to land lots of AOE hits.