Boss Fight Ideas that I think would be cool to see in the Campaign or in later expansions.
You have to fight a jetpacking Brute in a large silo or pit with floating platforms. Below you is a rising field of energy that will (kill or greatly damage you) if it catches up. So maybe you have to keep moving upwards while shooting the Brute, but if you manage to land a melee, it knocks him into the energy for big damage. Maybe he has a phase 2 where he whips out a hammer/repulsor to knock you back if you get too close.
A boss that uses a modified banshee with extra weapons and shields. You have to dogfight him while he’s accompanied by skimmers or other banshees. But if you can skyjack him, he uses his jet pack to try and re-skyjack you, but if you can stay away from him he’ll be easier to kill.
I’d like to see a boss that encourages you to use the repulsor to launch back projectiles at them (ravager or rockets). While you can damage this boss with normal weapons, reflected attacks do more damage. Perhaps a reverse version of this boss exists where you CAN’T use projectile weapons or he’ll reflect them back at you.
A simple mongoose race where if the boss beats you to a group of marines, he kills them and the checkpoint resets… or maybe it doesn’t.
Heretic Leader done right. Boss fight begins with HL cloaked and the two holograms attack. You kill them then the HL returns and drops two more, but he fights alongside them. If you kill the holograms first, he enters phase 3. Here he drops two more drones, but one has a carbine and the other has a sword and the real one has the dual plasma rifles. Kill the real HL in phase 2 skips phase 3.
A grunt with a heavy weapon, supported by endless waves of suicide grunts. Maybe in a narrow space giving less room for maneuvering.
(I have no idea if the repulsor is even in the campaign)