Got trashed by Irastikaan (some mild spoilers inside)

[worstcase11]

Well I had that quest with retriving the globe solved - and used the scroll. Did not go yet to get the quest reward and instead entered the dungeon with Musa first and last quest before she is gonna skip town.
We ran into Irastikaan for some reason - the entity from the globe quest and he pretty much wiped the floor with the entire team.
I had the feeling that might have been avoidable if I had the right item with me? He muttered something about 'releasing' him
Any hints what I can do to avoid a repeat performance?

[Scourge]

Late to the party.
But you are handed an academy scroll before jumping over an edge. Use it.