Wernog, Rider's Chaplain is a rare Legendary Creature — Human card from Secret Lair Drop (SLD), collector number 347. Current market price: $8.84 (foil $7.10), TCGplayer market prices via Scryfall.
When Wernog, Rider's Chaplain 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. Partner—Friends forever (You can have two commanders if both have this ability.)