Shards of insanity

When this card enters the battlefield, put
5 insanity counters on Shards of insanity.
At the beginning of each upkeep, put an
insanity counter on Shards of insanity.
At the beginning of your combat step,
you may remove X insanity counters.
If you do, X creatures gain deathtouch,
lifelink, and double strike until end of turn.
Sacrifice those creatures at the
beginning of your end step