2 cards where the name includes “undermine”

Akki Underminer (Champions of Kamigawa #155)

Akki Underminer {3}{R}

Creature — Goblin Rogue Shaman

Whenever Akki Underminer deals combat damage to a player, that player sacrifices a permanent.

“Deep inside the Sokenzan Mountains, a band of akki discovered a cache of ancient items of power. Their ensuing spree of destruction became known as ‘The Three Days of Fun.’”
Observations of the Kami War

1/1

Illustrated by Thomas M. Baxa

Standard
Alchemy
Pioneer
Explorer
Modern
Historic
Legacy
Brawl
Vintage
Timeless
Commander
Pauper
Oathbreaker
Penny
Undermine (Duel Decks: Ajani vs. Nicol Bolas #62)

Undermine {U}{U}{B}

Instant

Counter target spell. Its controller loses 3 life.

“Which would you like first, the insult or the injury?”

Illustrated by Massimilano Frezzato

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

The arc of my blade has carved a path of light to the end of these results.