have 0.001% idea what that means here it is my 0.001% idea is... is the Kings InDian?
Budapest Gambit

have 0.001% idea what that means here it is my 0.001% idea is... is the Kings InDian?
Are you 4 years old?

Isn't the castle at 15 (0-0-0) illegal? (castling through check)
No that move is legal, the rook can move through check but the king can't.

KID means King's Indian Defence.
4...Bc5 is tempting since it wins back the pawn, but 4...Nc6 is in my humble opinion better.
One of tha advantages of the Budapest is that it works well against players who play the Samisch/4 Pawns KID.