Leonardo, Sewer Samurai

Commander is where Leonardo, Sewer Samurai does its best work — the 101-card singleton format gives you room to run the Solemnity package alongside proliferate payoffs, and Leo's ward ability is meaningfully harder to play around at a table of three opponents. In competitive 60-card formats like Modern and Pioneer, the self-poison liability is a serious strike: aggressive decks can race you, and control decks will happily let you tick yourself toward ten. Legacy and Vintage have too many efficient threats to justify the risk unless you're already deep in a Solemnity shell. Standard is the exception worth watching — if Solemnity rotates out of reach, Leo loses his most reliable safety valve, but in a Standard environment where both coexist, the combo is easy to assemble and hard to ignore.