In hindsight...
The reasons to not use grabbow:
1. I knew Oni will use a duo involving upped dragons and wanted to discord his brain (though i expected him using aether duo).
2. I needed some spare novas vs
(I'm terribly sorry we finally didn't use them in the rol/hope deck, we were busy with support battles and i totally forgot it)
This was a terribly risky move that worked only 50%.
On the other hand, i think with a grabbow we would still lose the
battle, and i'm also not sure our grabbow could have beaten the huge dragons.