Irelia likely to ally with the order of shadows.
Going off of Irelia’s interactions it seems to me that she would ally herself with the order of shadows. First of all in her taunt to Kinkou members she says she doesnt care about balance and that the only thing that matters to her is Ionia’s victory. This is very similar to the order of shadows method of operating in which in order to obtain victory they use any means neccesary to gain power, such as zed and his shadow technique or Kayn with his attempt at conquering Rhaast. Irelia’s taunt towards Riven also shows that she would view Noxians who fight for Ionias cause as redeemed which means she would have no issue with Kayn’s history. When Irelia addresses Ionian loners or vastaya she pushes them to join together despite any differences in the unified cause of protecting Ionia. So it seems to me that it is very likely that Irelia would ally or atleast heavily consider allying herself with the order of shadows if it were for the future of Ionia.
This would be a pretty cool narrative story to look into since it would touch upon how far Irelia would be willing to go to defend her home and if she went as far as allying with the order of shadows, what would be the consequences of such an action and would she regret it?
Also it just occured to me she would probably be okay with working with the Ionian cabal and Jhin since they also havethe same goals.