Hello!,
I found something regard this matter.
In the challenger events guidelines says that it depend entirely on the players to keep the game in a proper state and "If a player forgets to use an effect during the timing specified by that effect, they cannot retroactively use it.".
But doesn't answer my question, is a special condition is mandatory?, what happens if you forgot to put the special condition or if u miss the special condition rule?
Kinds Regards