Actually, it's probably because of Agares that Steren's at that disadvantage -- I still maintain that she'd probably have curb-stomped Goruvich with little difficulty.
I've never intended her to quite be that powerful. Obviously her limits vary a bit, dependent on how well she can maintain her focus, but she's still finitely fast (and Marines are a fair bit faster than they have right to be as well) and not clad in thick armour plate.
The odds somewhat depend on if a Marine know they're fighting a biokine. Wildly underestimating her probably would result in a very short combat, likely finishing with her snapping the Marine's neck.
I figure that's probably the easiest way for her to kill a Marine - she's strong enough to do it, and it focuses an attack on a weak-point in both the Marine's physiology (unlike most other internal organs, they don't have a redundant spare for their spine) that the armour can't protect very well (it's a flexible joint, so can't be reinforced as well as other areas).
If they were taking her as a serious threat though, a Marine would definitely have fair odds. From which perspective, Agares may have one of his biggest advantages - what with his daemonic perception of the warp (and apparently some sense for biology), he's not going to mistake her for benign.
Well, there goes the image of Steren kicking Agares to the curb while wearing a backless dress and Combat Stilettos.
The boots aren't
quite stilettos. But frankly, if anyone can pull off fighting in high heels, a biokine with hyper-agility and invulnerability to such things as sprained ankles (at least while boosted*) probably has the best chance.
*And fairly resistant even while not, I suspect. Given the level of re-engineering she's done to herself, she's probably less prone to normal biological failings.~~~~~
Two more things.
#1: It has occurred to me that Goruvich had a bolt pistol. a) Does Agares still have this, and b) would he be using it*?
*Obviously not at the same time as riding the bike and wielding a sword.Unless you've got particular reason for him to shun it, I'd quite like to include it to help the flow of the fight.
#2: If his bike is mounting a weapon, does a grenade launcher (primarily for crowd control) sound alright for an Arbites bike? Although I suspect gas grenades might be the typical load-out, I'm thinking it's not that unlikely it was loaded with something a bit more lethal when cultists started showing up.