(NOTE: The text is somewhat blurry. Some of the words may not be accurate)
Spell Proof Armor
Keith/Skill
Activate this Skill during your Main Phase. All Machine monsters you control are unaffected by your opponent’s Spell effects. You can Normal Summon Machine Normal Monsters with 1 less Tribute. If a non Machine monster is in your GY, flip this skill over. This Skill can only be used once per Duel.

You can find more info about the locations in the official pages: Scars of Battle event, Rokket Revolt event.