Darkest of Forces

While active on the battlefield, every time
a samurai is killed place one 2/2 red
Demon Samurai token onto the battlefield.
Alternatively, you can place a +1 counter
on this card for each samurai killed.
When the total count reaches six, search
your library for any Demon (oni) creature
and play it to the battlefield attacking.
Then shuffle your library and exile this artifact.