Helo marines

there is this game Spacehulk Deathwing, but is first person

would these spacehulks fit in this game? they are bigger and slower but powerful

Spacehulks refer to the spaceships that game takes place on. What you're asking about is terminator armour and yes, it would be AWESOME to have in this game but I doubt it will ever happen officially. Maybe someday with mods like the first game.

There ARE Terminators in this game already, BUT they're only on the Chaos side during any of the Chaos themed missions.

Yes of course, I meant it would be awesome to PLAY as terminators

Would be nice to get a 1st company squad, yes. Maybe a terminator version of the bulwark, heavy, and tactical since those are the only classes that the game has that make sense to use the less maneuverable but more heavily armed and armored tactical dreadnaught armor. Or maybe give us a librarian and have him be in terminator armor as they often are, same goes for apothecaries.

Space hulks definitely fit into the concept of this game as they frequently contain tyranids or tyranid mutants. However, in third person you'd have bad time as some corridors can be really too narrow to move the camera. Deathwing was a great game, tho.

There is nothing against adding terminators as playable class, or dreadnoughts for that matter, problem is making a game mode where they belong, as they are way, way too powerful for pvp/coop that we have now.

But perhaps for this upcoming horde mode. If that is wave survival, then adding a drop pod that delivers a terminators armor when you have reached a set number of waves could deffo be a thing.

But we have zero info of how the horde mode will be at current time.