If we're sharing ideas, I'd like to point to the link in my signature, Manta Ray.
And since that fits under creature auras, I think it's worth reminding people that auras can be in almost any shape, as long as it's not super complicated like "the creature two slots down and four to the left gains +2|+2 every turn" (not necessarily super complicated, but much more complicated than it should be). They don't have to be every single adjacent creature. It can be adjacent to the sides, or maybe above and below, or just all creatures on the same row/different rows.