on damage of a player:
	victim is player
	message "&c%damage%ダメージを受けた!" to victim
	stop
on damage of a entity:
	attacker is player
	message "&c%damage%ダメージを与えた!" to attacker
on damage of a player:
	victim is player
	attacker is player
	message "&a[PvPSystem]&c%damage%ダメージを与えた!" to attacker
	message "&a[PVPSystem]&c%damage%ダメージを受けた!" to victim