Blazing Time Bomb

Timer 5 (This permanent enters the battlefield with 5 fuse counters on it. At the beginning of your upkeep, remove a fuse counter from it and you lose X life, where X is the number of fuse counters on it. When the last counter is removed sacrifice it.)
When Blazing Time Bomb leaves play, if it had no fuse counters, it deals 15 damage to target opponent.