Well i mean, you are going to play a soul return into a construct of Wraithbone when they implement Wraithguard at one point, so they wont be the first unit with an incorporeal "pilot".
No matter the form of the game, you'll get to respawn after dying. So there is going to need to be some suspension of disbelief anyway. It isn't a huge deal to temporarily control a daemon machine instead of a gene-enhanced human wearing power armor (or filthy Xenos if you are into that)
Or, you can simply be the deamon bound within the engine. Since Brent already expressed his wish to make deamons their own faction.
Did he? that'd be pretty cool. I do wonder how 'allied' factions are going to work, if you could invite a Daemon to your guild for example.
I wouldnt worry about it, Chaos welcome all. Plaguebearers will probably need to wipe their feet first though.
Don't know why, but you just gave me an idea. Imagine far in the future of the development of this game. The fight spreads to other parts then Arkhona. (Pretty sure they mentioned that would happen.) Imagine that when you possibly Warp Travel to another fighting zone, you could be invaded by Daemons. (Perhaps if the Server is full?) Battleground would be onboard the ship, but Daemons popping up here and there. You would be allied with those that are travelling aswell. This would be alot of work, but so worth it. Who wontz ta' wait fer' da' foight?! Da' Daemons pop up fer' enta'tainment anyway, once we'z 'eadin' fer' da' foight! If Chaos would get Daemon Engines, what would the equilavent be to other factions though?
eldar be the wraith units. Space marines get either a storm raven or one of the MANY flavors of dreadnought. Orks get either a deff dread or the gork/morkanauts. Reason why i asked daemon engines is cause unlike everyone else (even the orks) the daemon engines have a wider variety.
Also forgot that for transport vehicles, on a roll of one the daemon eats one of the passengers. I always pictured the non transport vehicles to be operating on their own. While a possessed rhino or land raider if you are bold/dumb enough to go into one will open on its own, drive on its own and maybe eat you via daemon leaping at you