So I finally was able to make a start on my Alpha Legion warband; The Last Surprise. I picked up the old start collecting chaos space marine box, since the Master of Possession is a much better HQ stat wise for the Alpha Legion than the combat patrol's dark apostle. I decided to go with a metallic paint scheme that I'm using based on this video: I picked up some sector imperialis bases for the legionary rank and file but i ran out of money so i used regular bases for the possesed and obliterators and a recycled sigmar base for the master.

I haven't got any experience with that varnish, so I can't say for sure, although logically it should (I know Vallejo's matt varnish will matt Vallejo Metal Colour paints). If you're worried about it, I'd say try a coat of Lahmian Medium (on the basis that if it looks OK to you before the varnish step, it won't magically become glossy after it )