Kira, Great Glass-Spinner

Flying
Creatures you control have "Whenever this creature becomes the target of a spell or ability for the first time each turn, counter that spell or ability."

Muddle the Mixture

Counter target instant or sorcery spell.
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Bane's Contingency

Counter target spell. If that spell targets a commander you control, instead counter that spell, scry 2, then draw a card.

Archaeomancer

When this creature enters, return target instant or sorcery card from your graveyard to your hand.

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

Dissolve

Counter target spell. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Neutralize

Counter target spell.
Cycling {2} ({2}, Discard this card: Draw a card.)

Island

Sinister Sabotage

Counter target spell.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dissipate

Counter target spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Refute

Counter target spell. Draw a card, then discard a card.

Negate

Eluge, the Shoreless Sea

Eluge's power and toughness are each equal to the number of Islands you control.
Whenever Eluge enters or attacks, put a flood counter on target land. It's an Island in addition to its other types for as long as it has a flood counter on it.
The first instant or sorcery spell you cast each turn costs {U} (or {1}) less to cast for each land you control with a flood counter on it.

Archmage's Charm

Choose one —
• Counter target spell.
• Target player draws two cards.
• Gain control of target nonland permanent with mana value 1 or less.