Mystical Dispute

This spell costs {2} less to cast if it targets a blue spell.
Counter target spell unless its controller pays {3}.

Faerie Vandal

Flash
Flying
Whenever you draw your second card each turn, put a +1/+1 counter on Faerie Vandal.

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Island

Frogify

Enchant creature
Enchanted creature loses all abilities and is a blue Frog creature with base power and toughness 1/1. (It loses all other card types and creature types.)

Syr Elenora, the Discerning

Syr Elenora, the Discerning's power is equal to the number of cards in your hand.
When Syr Elenora enters, draw a card.
Spells your opponents cast that target Syr Elenora cost {2} more to cast.

Gadwick, the Wizened

When Gadwick, the Wizened enters, draw X cards.
Whenever you cast a blue spell, tap target nonland permanent an opponent controls.