Corruption of Towashi

When Corruption of Towashi enters the battlefield, incubate 4. (Create an Incubator token with four +1/+1 counters on it and “: Transform this artifact.” It transforms into a 0/0 Phyrexian artifact creature.)
Whenever a permanent you control transforms or a permanent enters the battlefield under your control transformed, you may draw a card. Do this only once each turn.

Shatter the Source

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for or one mana of that creature’s color.)
Choose one —
• Shatter the Source deals 6 damage to target creature, planeswalker, or battle.
• Destroy target artifact.

Hurkyl’s Prodigy

When Hurkyl’s Prodigy enters the battlefield, create a tapped Powerstone token.
Whenever Hurkyl’s Prodigy attacks, you may pay . If you do, Hurkyl’s Prodigy can’t be blocked this turn and it perpetually gets +2/+0.

Legions to Ashes

Exile target nonland permanent an opponent controls and all tokens that player controls with the same name as that permanent.

Royal Warden

Phalanx Commander — When Royal Warden enters the battlefield, create two tapped 2/2 black Necron Warrior artifact creature tokens.
Unearth (: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)