Ah, the good ol' unupped rareless Decay counter with Emerald Shield that only worked consistently for me and a handful of other people x)
Mind you, that one worked off of QP's. That way you can pack more copies of the combo for more mid- and late-game total offence. That's a big problem of this deck: it doesn't do much damage. I love the spin you put on it with Rustlers and Devourers though, but I simply cannot stand needing two Novas for a Devourer and then having to wait for the next one, then the next one, etc.. then a Vamp and the combo. Sadly you're susceptible to CC because you need Rustlers, to bad hands because you need two Novas, and to a PC rush because you have no CC. Only Fogs.
Ideally healing should be coupled with CC. Other stalling works too in most cases. That's easy to fit in a rainbow deck. If you want a stable variant, try using QP's, more of the combo and either some CC spells from here and there or 6 Sundials. In conclusion, love the Rustlers, hate the non-Darkness mark. Nice one, made me nostalgic.