Suggestion:promotion to royal

You can choose to promote to royal or not

BUT

the original royal has to be discarded

therefore in this

you can promote your pawn to a royal queen like this

(queen is royal)

and check black

REMINDER:In n-check if you promote to royal the remaining checks will be the same as the original royal before promotion

also you can choose not to promote to royal

https://www.chess.com/variants/custom/game/2165346/0/1

Wait does the original royal have to be in check?

no