Signature series ideas:
Halo 2 version of the scarab/Super Scarab from Halo Wars
Figures: a young prophet of regret (wears green instead of the colour he wore in the original halo 2 (I think it changed in H2A) and looks a bit different), 2x Red V1 elites with updated articulation (they're closer to HW elites than the V2s) with HW style honorguard staffs (less ceremonial than the H2 ones), 4x blue V1 elites (again updated articulation) with 2x plasma rifles and 2x needlers.
UNSC Longsword
Room for at least 2 crew (dont want it to be too big but also not too small) also includes a fuelling vehicle and maybe a weapon rack similar to CODs strike jet set
Figs: 2x H3 Pilots, 3 ground crew