Noncreature spells with converted mana cost 4 or greater can't be cast.
Noncreature spells with in their mana costs can't be cast.

Search your library for a card, put that card into your hand, discard a card at random, then shuffle your library.

Flash
When Garna, the Bloodflame enters the battlefield, return to your hand all creature cards in your graveyard that were put there from anywhere this turn.
Other creatures you control have haste.

, Sacrifice Generator Servant: Add . If that mana is spent on a creature spell, it gains haste until end of turn. (That creature can attack and as soon as it comes under your control.)

, Exile Ghoulcaller's Accomplice from your graveyard: Create a 2/2 black Zombie creature token. Activate this ability only any time you could cast a sorcery.

, Discard two cards: Return Ghoulsteed from your graveyard to the battlefield tapped.

Flying
, Sacrifice Glen Elendra Archmage: Counter target noncreature spell.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

When Golgari Brownscale is put into your hand from your graveyard, you gain 2 life.
Dredge 2 (If you would draw a card, you may mill two cards instead. If you do, return this card from your graveyard to your hand.)

Choose one —
• All creatures get -1/-1 until end of turn.
• Destroy target enchantment.
• Regenerate each creature you control.

Golgari Grave-Troll enters the battlefield with a +1/+1 counter on it for each creature card in your graveyard.
, Remove a +1/+1 counter from Golgari Grave-Troll: Regenerate Golgari Grave-Troll.
Dredge 6 (If you would draw a card, you may mill six cards instead. If you do, return this card from your graveyard to your hand.)

When Golgari Thug dies, put target creature card from your graveyard on top of your library.
Dredge 4 (If you would draw a card, you may mill four cards instead. If you do, return this card from your graveyard to your hand.)

Return target legendary creature card from your graveyard to the battlefield. That creature gains haste. Exile it at the beginning of the next end step.
Splice onto Arcane (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Madness (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)
When Grave Scrabbler enters the battlefield, if its madness cost was paid, you may return target creature card from a graveyard to its owner's hand.

Choose target creature. Mill three cards, then put a +1/+1 counter on that creature for each creature card in your graveyard.

: Return target basic land card from your graveyard to your hand.

Delve (Each card you exile from your graveyard while casting this spell pays for .)

Sacrifice Heap Doll: Exile target card from a graveyard.

When Heliod's Pilgrim enters the battlefield, you may search your library for an Aura card, reveal it, put it into your hand, then shuffle your library.

Aura spells you cast cost less to cast.
Heroic — Whenever you cast a spell that targets Hero of Iroas, put a +1/+1 counter on Hero of Iroas.