Door to Insanity

At the beginning of your upkeep, put a sanity counter on Door to Insanity,
then put the top card of your library into your graveyard for each sanity
counter on it.
{t}{u/b}{u/b}:Remove all sanity counters on Door to Insanity,
then each opponent puts the top X cards of their library into their graveyard,
where X is 2x the amount of counters
removed this way.