Xilnato, the Final Thorn

Deathtouch
All other creatures get -1/-0.
When Xilnato enters the battlefield, put 3 timer counters on Xilnato.
At the beginning of your upkeep, remove a timer counter from Xilnato. When Xilnato has 0 timer counters on them, destroy all other creatures.
"The time will come, the time will end" -Xilnato