at the beginning of each end step, if it's an opponent's turn, put a +1/+1 counter on discordant spirit for each 1 damage dealt to you this turn.
at the beginning of your end step, remove all +1/+1 counters from discordant spirit.
at the beginning of each end step, if it's an opponent's turn, put a +1/+1 counter on discordant spirit for each 1 damage dealt to you this turn.
at the beginning of your end step, remove all +1/+1 counters from discordant spirit.