So jelly ; ;
I would go for dazzling since it opens you to attack any unit, and if you go the Savage Blow route, that's how you rack up damage anyway. If she's +spd, you maay get away with wrathful to attack mages and maybe even some archers but I'm a little paranoid about it.
Unrelated note, I said the opposite in an earlier post, but blessings do in fact affect arena score. It's because the stat boosts are treated as part of your BST, so a unit with a water's blessing is treated as being +6 BST above its natural one. This would most benefit units with BSTs ending in either xx4 or xx9 since it would boost their BST bins up by two. Fjorm is 164 BST, so if she were to replace an armor unit of 170-174 BST, then you would need at least two more bins worth of boosting, after which any further increases in bins is a profit in points.