While you cant attack your opponent with Treasures (Under most circumstances), you can use them to power out huge threats, or fuel artifact engines like Mirkwood Bats
Spend two of every type of Mana and tap to Sacrifice The Bridge of Death: Target player loses the game
These aren't all "high ceiling" cards that could be considered "wincons" but I'm hoping this is a case where the whole is greater than the sum of its parts
Dandn Not actually a Commander-relevant card, but worth an honorable mention because this innocuous blue creature is responsible for inspiring an entire format, known as Forgetful Fish
When the ring is on Frodo, you get to draw up to 3 cards per attack via the combination of rings and abilities
Sauron, the Dark Lord Sauron, the Dark Lord has the most pushed ward text weve seen, and itll feel like hexproof against a lot of decks