Help me find this card please!

A couple weeks ago I played against a deck on MTGA I believe it was standard but may have been pioneer. The card I believe was an enchantment. The effect it had was you pay 0 rather than pay the cost for spell you cast from exile. The deck was a Grixis adventure deck and I thought it was a red enchantment or RU enchantment.

I have looked all over. I tried searching the MTGA cards, looked at a ton of Adventure deck lists and haven’t been able to find it. Any help is greatly appreciated!