Gitaxian Spellstalker

Trample, ward {2}, prowess, prowess (Each instance of prowess triggers separately.)

Khenra Spellspear

Trample
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
{3}{U/P}: Transform this creature. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Khenra Spellspear // Gitaxian Spellstalker

Invoke Despair

Target opponent sacrifices a creature of their choice. If they can't, they lose 2 life and you draw a card. Then repeat this process for an enchantment and a planeswalker.

Blazing Rootwalla

{R}: This creature gets +2/+0 until end of turn. Activate only once each turn.
Madness {0} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Mountain

Feast of Sanity

Whenever you discard a card, this enchantment deals 1 damage to any target and you gain 1 life.

Terminal Agony

Destroy target creature.
Madness {B}{R} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Bone Shards

As an additional cost to cast this spell, sacrifice a creature or discard a card.
Destroy target creature or planeswalker.

Swamp

Tormenting Voice

Argentum Masticore

First strike, protection from multicolored
At the beginning of your upkeep, sacrifice this creature unless you discard a card. When you discard a card this way, destroy target nonland permanent an opponent controls with mana value less than or equal to the mana value of the discarded card.