Gelectrode

{T}: Gelectrode deals 1 damage to any target.
Whenever you cast an instant or sorcery spell, you may untap Gelectrode.

Mountain

Mercurial Geists

Flying
Whenever you cast an instant or sorcery spell, Mercurial Geists gets +3/+0 until end of turn.

Brute Force

Target creature gets +3/+3 until end of turn.

Serum Visions

Voracious Reader

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Curious Homunculus

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.
At the beginning of your upkeep, if there are three or more instant and/or sorcery cards in your graveyard, transform Curious Homunculus.

Curious Homunculus // Voracious Reader

Island

Samut's Sprint

Target creature gets +2/+1 and gains haste until end of turn. Scry 1.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Electrolyze

Electrolyze deals 2 damage divided as you choose among one or two targets.
Draw a card.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Wee Dragonauts

Flying
Whenever you cast an instant or sorcery spell, Wee Dragonauts gets +2/+0 until end of turn.

Mana Leak

Counter target spell unless its controller pays {3}.

Double Cleave

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Schismotivate

Target creature gets +4/+0 until end of turn. Another target creature gets -4/-0 until end of turn.