For Challenge # 112. I wanted an ability that represented the fact that Roamers tend to move around, but not necessarily attack. 'When the creature untaps' works fine, but roaming doesn't infer constantly running around. Once per turn makes more sense in my mind. This mechanic could also use support from abilities or costs that happen to tap your creature. Some themed equipment would go a long way.

Hmm, I like the mechanic, although the easiest way to achieve this makes me think of the creature staying put which doesn't seem like roaming to me, but hey, we all see things differently.

If you have the tap effects asking the Roamers a flavor of movement, this mechanic would fit then quite nicely. However, Restless compares unfavorably to Inspired, doesn't it?

It does. But that just allows for larger effects, and better stats. I don't know if that's argument enough. I doubt, for example, that we'll ever see shroud again, now that we have hexproof. The same could be said for Persist.

I didn't think we'd ever see shroud again, either, but if I remember correctly Maro has said it's not impossible.
Persist, on the other hand, is to me a completely different animal than Undying, and could very well reappear.