However, instead of being able to add counters itself, Omarthis gets additional counters whenever you put more plus-one plus-one counters on other permanents
So with these four packs, you could have a red and black Bloody Graverobbers deck, or a red and white Bloody Legion deck, for example
But even if they dont, you can activate its ability to force them to draw a card after their initial one so you get another card as well
If the gift was promised and the target is illegal as Valley Rally tries to resolve, it won't resolve and none of its effects will happen
Putting cards in because they looked cool or were fun, or just fit with the theme so well
Using any of these tools requires branching out into two or three colors, but that shouldnt be too much of a problem