Consequences in killing Marazhai?

Now don't get me wrong my RT is an iconoclast all the way and I always support interspecies co-operation which is why I let the Aeldari have Janus (instead of leaving it defenseless and or open to Chaos corruption...again).

but

I have this very deep and reallllly guttural urge to just hand this piece of xenos filth over to the inquisition the moment I escape Commorragh. I am just asking for a quick spoiler but if we were to say bring him on our journey and help him with whatever companion quest he has, will the galaxy benefit from it in any way? Will he change better in any way? Or will it actually be better if I just gave the inquisiton a little apology gift for being captured?

That is all :)