One important thing to notice about the Baeru move : try to do it when your opponent can't punish it at once.
I played it when my opponent was at 0f, so theorically, he could have used Prayer and +1f from wheel to drop a Last Nightmare, but that was very unlikely as he didn't use Prayer the turn before after attacking. So, apart from a Prayer topdeck and a Last Nightmare already in his hand, it was safe.
Conversely, if you play rush against Blue and have a LN in hand (not sure if it was the case here), try to keep some resources to be able to play it any time your opponent has a possibility to throw Baeru (well, I admit that discounted Baeru was not easy to predict ^^)
Baeru is the threat that can completely wreck your game, but you could also catch some other troublesome creatures (Collossi, Archons ...), so even if your opponent has no Baeru, that's not a worthless move