[THE FIFTH GATE OPENED!]
Valid:
At the beginning of your turn, place a Ninja Blade coin (symbolizing a Gate coin) on this Ninja. For every Gate coin on this Ninja, this Ninja gets +1/+0. When you place the 5th Gate coin on this Ninja, discard this Ninja at the end of that turn.
"One more and we are finished! The fifth gate - Gate of Closing ... open!!"