The Spiral

Patron - The Spiral can be your commander. If
it is, whenever you cast a spell, counter that spell.
Reveal cards from the top of your library until
you reveal a card that shares a card type with it.
You may cast it without paying its mana cost.
Shuffle the rest of the revealed cards into your
library.
At each upkeep, that player gains control of
The Spiral. It becomes their commander until
end of turn. (It is still your commander.)