Yes, "If the number of DON!! cards on your field is equal to or less than the number on your opponent's field, give up to 1 of your opponent's Characters -2000 power during this turn and this Character gains [Rush]." Up to means you can choose 0, then gaining rush is also automatic and not optional
![[OP09] Black/Purple Luffy vs. Purple Luffy || 3on3 Wave 2 Autumn || One Piece Trading Card Game](http://i.ytimg.com/vi/ULSxDT863F4/mqdefault.jpg)
Does Ichiji effect can be use if is no opponent’s character on play? To minus and rush?
Yes,
"If the number of DON!! cards on your field is equal to or less than the number on your opponent's field, give up to 1 of your opponent's Characters -2000 power during this turn and this Character gains [Rush]."
Up to means you can choose 0, then gaining rush is also automatic and not optional