cards like propaganda mtg (381) - Foil - Reversible Borderless - Magic: The Gathering » Magic: The Gathering Singles » Secret Lair Singles English Print Propaganda · Assassin's Creed (ACR)

If Sandswirl Wanderglyph leaves the battlefield on a turn in which an opponent attacked you or a planeswalker you control (perhaps because it died in combat or another player cast a spell that destroyed it), that opponent can cast spells

even though that mana is restricted to casting your commander, its still the Commander equivalent of a Black Lotus, the most sought-after card in Magic history (well, except for The One Ring)

Electrolyse is all round harder to cast than Fire / Ice

Tekuthal, Inquiry Dominus decks get four proliferate effects and you'll make a few in a Hapatra, Vizier of Poisons deck as well

Strategies utilizing multiple permanent types in 1 or more engines with low CMC cogs are also quite viable and extremely dangerous even in environments with a reduced card pool