Saskia the Unyielding

Vigilance, haste
As Saskia the Unyielding enters the battlefield, choose a player.
Whenever a creature you control deals combat damage to a player, it deals that much damage to the chosen player.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Warstorm Surge

Whenever a creature enters the battlefield under your control, it deals damage equal to its power to any target.

Where Ancients Tread

Whenever a creature with power 5 or greater enters the battlefield under your control, you may have Where Ancients Tread deal 5 damage to any target.

Urza's Incubator

As Urza's Incubator enters the battlefield, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Molten Echoes

As Molten Echoes enters the battlefield, choose a creature type.
Whenever a nontoken creature of the chosen type enters the battlefield under your control, create a token that's a copy of that creature. That token gains haste. Exile it at the beginning of the next end step.