i was thinking a AHSS with a bladed variant would be cool the blades could be 1 black and 1 silver to match his gun colors.
this is a good clip it shows his guns and that red mist over him while
he is feeding might make good gas (its a little Gorey all animated tho)
https://www.youtube.com/watch?v=-PooRVkhQ9whttps://www.youtube.com/watch?v=w1mOeuI8JOshttp://imgur.com/gallery/iNQt6https://imgur.com/t/hellsing_ultimate/9D3NuIN this wispy blood like stuff would be good gas or weapon swipes
https://imgur.com/t/hellsing_ultimate/EnRh1gFor this might also work