Aether Helix

Return target permanent to its owner's hand. Return target permanent card from your graveyard to your hand.

Plains

Mountain

Aggressive Instinct

Target creature you control deals damage equal to its power to target creature you don't control.

Island

Ink-Treader Nephilim

Whenever a player casts an instant or sorcery spell, if that spell targets only Ink-Treader Nephilim, copy the spell for each other creature that spell could target. Each copy targets a different one of those creatures.

Aggressive Biomancy

Create X tokens that are copies of target creature you control, except they have "When this creature enters the battlefield, it fights up to one target creature you don't control."

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on the top or bottom of their library.

Forest

Afterlife

Destroy target creature. It can't be regenerated. Its controller creates a 1/1 white Spirit creature token with flying.

Aether Mutation

Return target creature to its owner's hand. Create X 1/1 green Saproling creature tokens, where X is that creature's mana value.