Blessing for Raven (Basilikos + Fury)

Just give him Life and Death 6 (Life and Death 3 A skill). His attack is already really high, so you could give him a blessing that increases attack or speed.

Both would work nicely on him. Considering that he is a PP-based unit, a single hone spd can already bring his speed to 48 (or 50 if going with LnD as an A slot), which is usually enough for reliably doubling units on arena's offense.

In other words, while you can run him with Fjorm for definite doubling, you will usually find it more useful to gain that additional attack instead from VL Ike, meaning fire over water blessing, based on the legendary heroes that have been released so far.

I gave my Raven Water Blessing. He needs all the Speed he can get so that he can double and 1RKO anyone he faces against.

Only reason to give him Fury is if you're really skeptical on him surviving a hit. Otherwise, there's not of a point on building on his durability unless he's +Def. Double L&D make him disgusting.

With sky-high stats in both Atk and Speed it doesn't really matter. I think the question you should be asking is "who should he team up with?"

My vote is Fjorm (Water Blessing) as she'll be able to cover mages and reds that he may struggle with. If you have access to Like then he certainly can do well with him, just beware of mages.