Siegebreakers is a rare satyr unit that deals damage to nearby enemy structures on play. The damage done by Siegebreakers' ability can be increased by leveling it up. Siegebreakers can fit into any deck, but has specific synergies in satyr decks.
Siegebreakers works as an excellent counter to structures when it can be placed near them.
High movement units pair nicely with Siegebreakers, since it has to be played near the enemy structure in order to deal damage to it. Since most players place structures close to their own base, you would need those high movement units.
Structures that have to be placed near the middle of the battlefield, like Upgrade Point or Fort of Ebonrock, are easier targets for Siegebreakers to destroy.
There's a mild anergy here with Execution, as both cards give you means to shift troublesome structures without direct attack. If you run Siegebreakers you probably don't need Execution, and vice versa.
…deal 4 damage…
…deal 5 damage…
…deal 6 damage…
…deal 7 damage…
…deal 8 damage…
August 7, 2017: Decreased mana cost by 1
September 26, 2017: Set strength to 4 for all levels, increased damage at higher levels
November 16, 2017: Increased ability by 1
April 22, 2018: Bordering at all levels, gains +1 strength per level
October 1, 2020: Movement increased to 1, ability hits surrounding enemy structures