If an opponent use his Stand Off effect on an attack and you only have 1 foundation and your character ready, can you commit both to cancel their use of Stand Off?

I ruled you could, but the player i ruled against still wanted an official answer.

Since it become a cost to cancel (as stated in all the Stand Off vs Torn Hero topics ), i supposed you could use your character as a foundation... right?

Your character can count as a foundation to pay for a cost. It cannot be targeted by effects targeted at foundations.

Since it's been ruled that it's a cost (and thus doesn't trigger Torn Hero and the like) you can commit your character to pay it.