While Vren is on the battlefield, creatures your opponents control are exiled instead of dying, and abilities that trigger when a creature dies won't trigger
Artifact Creature Assembly-Worker Uncommon Toraji 4/4 NOT LEGAL Standard NOT LEGAL Future LEGAL Historic LEGAL Timeless LEGAL Gladiator LEGAL Pioneer LEGAL Explorer LEGAL Modern LEGAL Legacy LEGAL Pauper LEGAL Vintage LEGAL Penny LEGAL Commander LEGAL Oathbreaker NOT LEGAL Standardbrawl LEGAL Brawl NOT LEGAL Alchemy LEGAL Pauper Commander LEGAL Duel NOT LEGAL Oldschool NOT LEGAL Premodern NOT LEGAL Predh When this creature enters, you may search your library for an Assembly-Worker creature card, reveal it, put it into your hand, then shuffle.
This can turn even your tiny cat tokens into huge threats
Lead is a narrow effect, and just isn't worth it except if you decide to build your whole deck with the sole purpose of making this card playable, which a Johnny deckbuilder like yours truly will do, but almost no one else will ever bother doing
Despite all my complaining about how I wish this was a little better it is still a two mana counterspell and a cheap bounce card, both great effects to have access to
That is one awesome effect in a Commander game