Corrosive Mentor [Shadowmoor] Lightning[-30] Fighting[-30] when your opponent activates a

when your opponent activates a monster effect (except during the Damage Step) (Quick Effect): You can activate this effect

Set: World Championships 2013 Type: Item Rarity: Rare

If you control this card that was Xyz Summoned this turn by using an "Exosister" monster as material (Quick Effect): You can target 1 card your opponent controls or in their GY

2: Change 1 monster on the field to face-down Defense Position or face-up Attack Position

Set: Platinum: Base Set Type: Psychic Rarity: Rare Retreat cost: Colorless

Corrosive Mentor [Shadowmoor] Lightning[-30] Fighting[-30] when your opponent activates aSet: Shadowmoor Type: Creature Elemental Rogue Rarity: Uncommon Cost: {2}{B} Black creatures you control have wither. (They deal damage to creatures in the form of 1 1 counters.) Guttering cinders stoke their dying flames by snuffing out the lights of others.