This can go above and beyond... we could even have Christmas events where a dev plays as the Emparahh with OP weapons and health... and a santa hat.

...whoever kills him gets something.

I'm sure the devs will play the game like everyone else...

i imagine to see the dev spread in the playable faction tyranids will be controlled only indirectly ( by setting the ai)

Avatar of Khaine, anyone? I'm sure that the devs would've enjoyed being one

Maybe. I think I'd much rather be fighting side by side with Stephen as one of my Striking Scorpions than him as a faceless (or even named) tyranid monstrosity. I'm sure they want to play the game too, and not the antagonist all the time.

A Dev of GM behind the wheels of a controllable Carnifex or Hive Tyrant makes hide.