Hellbreakers have 2 gatling guns on its cockpit useful aganst infantry. When you upgrade hol27 Hellbreakers fire a HOL27 anti-air missile from above the gateling guns
Hellbreakers are incredibly effective aganst infantry even grouped infantry. The HOL27 missile easily takes out lightly armoured air units. This makes the hellbreaker effective aganist Myriad as it can take out swarms of Manglers and Venom Slingers and easily take out Dreadsnouts and Banekites.