Hardest thing ever

How does it work when white has 3 kings? Do the first 2 get captured without saying "check" or white needing to move them out of check while the final survivor, whichever one it is, needs to be mated?

It's interesting fact that the white has 2 more queens than the black, too. And 7 rooks against 4 - and inverse relation for knights. And only the one bishop against 5 black ones. While pawns are 12 against 8 and the one can transform into any figure already. So the white have 4 more pawns at all. If they turn first, I think, they win.