Dark Angels Veterans Showcase

Sternguard veterans are amongst my favourite Space Marine minis. They are essentially what a Space Marine should be, wearing ornamented power armour with different replacement parts, scrolls, necklaces, service studs and other blings to make each one stand out. Probably because of my love for Space Wolves, I just find the bog-standard vanilla squads boring, where the only difference is that the occasional skull in the helmet or chst plate. Now Dark Angels don't get Sternguard vets but I just couldn't resist to paint 5 for the greenwing. In game I will either use them as Tactical marines, or as allied SM sternguard.

Of course I still need to base them, but I'm still undecided. For me the bases need to fulfill 2 roles i) enhance the army by providing a rich contrast and ii) set said army in a context, for example a campaign I've read in a book. Now I'm fairly new to DA lore and as such I don't know much beyond them fighting greenskins, and color-wise I'd like to use the same bases for the Death, Raven and Green wings. Any ideas and recommendations are very appreciated!

Also here's a sneak peek at what's in my desk right now - the mighty DW Knights! alas I need to replace the needle on my airbrush so there will be limited progress this week. What do you guys think?