That's No Moonmist (Unknown Event #CG02b)

That's No Moonmist {1}{G}

Instant

Transform all artifacts and Phyrexian creatures on their front face. Prevent all combat damage that would be dealt this turn by creatures other than Phyrexians. (Only double-faced cards and tokens can be transformed.)

Standard
Alchemy
Pioneer
Explorer
Modern
Historic
Legacy
Brawl
Vintage
Timeless
Commander
Pauper
Oathbreaker
Penny