Vishgak, Bloodied By All

At the beginning of your upkeep, put a thirst counter on Vishgak, Bloodied By All
At the beginning of your end step, for each Thirst counter on Vishgak Bloodied By All, you may pay 1 life to put a +1/+1 counter on Vishgak.
At the beginning of each opponent's end step, for each Thirst counter on Vishgak, Bloodied By All, that player may pay 1 life to remove a +1/+1 counter from Vishgak.