Your all crazy!!!
If they are all there together like that, they'd obviously try to kill each other first. Now, depending on who won, this is what would happen:
I'm just going to assume that a space marine is a generic space marine from the ultrasmurfs. He would, I think, if he won the battle, capture you and your new tech and take you back to his captain, who would interrogate you, then when he learns of your new tech that can travel through time, he'd take you to the Marneus Calgar, who would probably try to prevent the Horus Heresy itself. With you hopefully being properly rewarded, since the Ultramarines tend to be fairly decent human beings, not 'killy killy, burny burny' like certain other sm chapters.
The Guardsman, who through some strange luck or martial prowess of the highest degree, won the battle, would probably ask you if you were an Adept of the Mechanicum, and then, depending on your answer, either take you back to his command, who would send you to Segmentum Command, and use your invention to win even more battles(or call an inquisitor). Or if you said you were Mechanicum, then just leave you alone, so you can go to another time that makes more sense.
An Inquisitor, who I assume is a moderate(neither puritan nor radical) will probably do a smart thing. Inquisitors are the best of the best of humanity,so I think, will probably see the value of being master of time and space. You will probably either be tortured and stripped of all your secrets, but hopefully the inquisitor will know just how fragile the human mind is, so instead either let you teach the mechanicum your secrets, or make you part of his retinue, where he travels through time and learns secrets and helps out humanity. Thus is the origins of The Doctor, former Inquisitor.
Now, the Farseer, probably already forseeing your arrival, had already had a webway gate built right where you would arrive, and when you arrive, reinforcements come and take you into the webway. Back at the Farseer's craftworld, he tries to be reasonable with you to help him stop the fall of the eldar. You agree, cause eldar are so peruasive, and the eldar are restored....what he doesn't tell you is that he also made sure to destroy humanity before it became a problem. You just got pwned.
The Ork Boy is too busy having the time of his life in an 8-way free-for-all. A Mekboy, on the other hand, would, if he won, kill you and loot the time-machine. Only having to believe that it works, he travels back in time and wages wars with every race that ever existed as well as races when they were younger, etc...
The Sorcerer, well, he probably already time travels all the time...
A Necron Lord probably would just flay you alive, and destroy you machine. Necrons have already invented time travel.
A tyranid would kill you as well. Tyranids don't use tech.
Well, hope you enjoy reading my opinion.:victory: