Donovan, Brother of Birds

When Donovan, Brother of Birds enters or leaves
the battlefield, each opponent may investigate.
Each opponent who doesn't loses 1 life. You
investigate X times, where X is one plus the
number of opponents who investigated this way.
(To investigate, create a Clue token. It's an artifact
with "{2}, Sacrifice this artifact: Draw a card.)
Friends forever (You can have two commanders if
both have friends forever.)