possible cards

***Artifacts***
Door of Destinies, (4), As Door of Destinies comes into play, choose a creature type. Whenever you play a spell of the chosen type, put a charge counter on Door of Destinies. Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Goblin King sideboard?

**Sideboard**

(3) Shattering Spree, Sorcery, R
Replicate {R} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)

(3) Relic of Progenitus, Artifact, 1
{T}: Target player exiles a card from his or her graveyard.
{1}, Exile Relic of Progenitus: Exile all cards from all graveyards. Draw a card.

Surgical Extraction, Instant, {BP} ({BP} can be paid with either {B} or 2 life.)
Choose target card in a graveyard other than a basic land card. Search its owner's graveyard, hand, and library for any number of cards with the same name as that card and exile them. Then that player shuffles his or her library.

Grafdigger's Cage, Artifact, 1 (1)
Creature cards can't enter the battlefield from graveyards or libraries.  Players can't cast cards in graveyards or libraries.

Rain of Gore, Enchantment, BR (2)
If a spell or ability would cause its controller to gain life, that player loses that much life instead.

Mark of Mutiny, Sorcery, 2R (3)
Gain control of target creature until end of turn. Put a +1/+1 counter on it and untap it. That creature gains haste until end of turn. (It can attack and {T} this turn.)