Kyztolis, Drowner of Worlds

Kyztolis, Drowner of Worlds enters the battlefield with x time counters on it.
At the beginning of each players upkeep, remove a time counter.
At the beginning of each players end step destroy all creatures but Kyztolis, Drowner of Worlds.
{5}: Put 2 time counters on Kyztolis, Drowner of Worlds. Any player may activate this ability.