It does seem a bit underwhelming. Thunderstorm hits every enemy creatures for 1 damage, although you do have to choose when to use it as opposed to this one that you can put out immediately and hope that it hits the right enemy creatures.
The interesting part about this is that the ability seems to be passive... which might mean you could Butterfly Effect it, quint it, and then it's an untouchable destroyer that damages a random opponent creature for 1 a turn. The only thing that could stop it is if nightfall/eclipse came into play and the opponent had a fire buckler/thorn carpace. Could replace Devourer as my favorite creature to use BE on.