I guess there's something I'm missing about the name Urf, unless it's just for fun.
It does function similarly to octo, but there's a key difference. Because octo's freeze lasts 3 turns, it can individually lock down 3 creatures (4 if upped) as long as you have the quanta for it, whereas this can only do one regardless.
With that comparison in mind though, should I perhaps lower the cost of it to 3?