Temple of time - Oblivion mobs ice weakness

I recently completed all of the temple of time quest's up to the " Road To Oblivion 1 " quest, I completed the quests leading up to this in anticipation that the Oblivion mobs would have a weakness to Ice spells, as I was told by numerous of people that they were weak to ice which I guess made me feel like I didn't need to check HiddenStreet. Long story short is that when I eventually got to oblivion, the mobs weren't weak to ice but instead poison.

I would like to request that these mobs would be made weak to ice as it would make sense seeing as the ice mobs before this map are weak to fire and the oblivion mobs being fire based should be weak to ice spells. It's understandable if this isn't possible but I wanted to post this anyway.