At the beginning of your end step, you may sacrifice another creature. If you do, reveal cards from the top of your library until you reveal a nonlegendary creature card with lesser mana value, put it onto the battlefield, then put the rest on the bottom of your library in a random order.
Sacrifice a creature each end step to dig and cheat a cheaper nonlegendary creature straight onto the battlefield, recurring value while assembling a sacrifice-fueled board. You ramp into expensive creatures, feed them to Kethek's trigger, and chain payoffs as bodies enter and leave to grind opponents out or assemble a combo finish.
Free, repeatable creature cheating every end step that snowballs board presence
Strong synergy with both death triggers and ETB triggers (double-dipping value)
Cheap, easy-to-cast 4-mana commander that immediately advances your plan
Aristocrats and reanimator overlap give the deck multiple angles to win
Trigger only fires on your end step, so it's slow without sacrifice or extra-turn enablers
Requires a high-mana-value creature to sacrifice to hit big payoffs, creating awkward gaps
Heavy reliance on the commander; repeated removal/exile shuts the engine down
Random bottoming and 'lesser mana value' clause can whiff if your curve is poorly built
No card draw or protection built in; needs supporting pieces
Each sacrificed creature forces opponents to sacrifice, dismantling their boards.
Tighten the creature curve so Kethek reliably hits impactful lesser-MV bodies, and add free sacrifice outlets (Viscera Seer, Carrion Feeder, Ashnod's Altar) plus Treasure makers to accelerate and enable loops. Layer in multiple aristocrat payoffs (Blood Artist effects, Mayhem Devil) so the engine wins even through interaction, and include commander protection and recursion like Lightning Greaves and Phyrexian Reclamation to keep the loop online.
Legendary Creature — Phyrexian Beast
