Whenever Storrev deals combat damage to a player or planeswalker, return to your hand target creature or planeswalker card in your graveyard that wasn't put there this combat.
Storrev is a midrange Golgari value engine: jam efficient creatures, trade and sacrifice them freely, then connect with Storrev's 6/5 trample body to recur your best threats from the yard. You grind the table out through repeated value, recursion, and incidental sacrifice synergies until your card advantage overwhelms everyone.
Built-in recursion engine that refills hands every time it connects
Naturally trampling 6/5 for 4 is hard to chump-block profitably
Pairs perfectly with sacrifice and graveyard strategies in the strongest two-color value pairing
Color identity gives access to the best removal, ramp, and recursion in the game
Recursion only triggers on combat damage, so it's slow and combat-dependent
Vulnerable to spot removal and chump-blocking that denies the trigger