Not as long because once you get 3 anchors of fog the trips to completing this are get very short LOL!
The 3 tear battles are VERY tough but since you are above the fog you need to waste and talismans or slots on reducing the fogs affects so use that to help you take down the realm tear fights.
AS for the Valkyrie boss she is always in the lop left corner of ivaldi's workshop but the boss here self is...not very tough her only attack that might be tough is when she shoots all those ice projectiles at you BUT you can just block most of them and doge the last one her attacks that flash yellow are annoying though as they need pretty tight dodge timing but besides that not that tough at all.
PS:Next time we go to the next and last optional realm.