Boomerang being first choice
The cards here would permanently change possession to the winner, making it so you were essentially gambling a random card in a game
This red instant is definitely an odd one: Fight spells are rather rare in red, but the double utility (removal plus ritual), on top of conserving your red mana for the whole turn, has made The Last Agni Kai very popular in casual Commander, and good enough to see cEDH play in Dargo, the Shipwrecker decks (usually with Tymna the Weaver as partner commander)
And Mental Misstep is the ultimate tempo card, countering key 1-drops like Sol Ring, Mystic Remora, or Vampiric Tutor before your opponent can even get going
I wouldn't recommend throwing Wheels like Wheel of Fortune or Windfall into the mix, though
At least this one can target creatures and hopefully keep the board clear while you do absolutely nothing else