I would say that it would be able to fair pretty well against them since you have ice type moves, and those are pretty major in the elite four fights I found out, to my dismay. The one thing that could help is a water type move.
Since it’s been 3 days you probably already beat the E4 but idk
Why in the world would you put Hurricane, a 70 accuracy special move, on a D. Bisharp that has 125 physical and 60 special attack?? It can get Acrobatics, which is 110 BP and 100 Accuracy without an item.
Flame Orb burns the holder, and with the moveset, it looks like Milotic is used to stall things with Toxic and Recover, but burn makes you take damage every turn, so ig you have Marvel Scale for the defense boost, but I’d say give it leftovers and use an X Defense or 2.
Tyranitar, idk what the purpose of Taunt is, maybe to shut down Kayla’s Smeargle? Smeargle is faster than Tyranitar, and unless it has a -Speed nature, it’ll probably spore you.