Arcane Bolt

[Baalz]

I don't know, 75% SR is fairly useful in enough situations that I wouldn't dismiss it out of hand even if you're not sure who you're gonna be fighting with. Lightning is often the goto way to fight off tougher units in the early-ish game, so if you're getting a benefit from the air shield and the SR it can be a better choice than other blesses, like when you're fielding toughish units with no shields and don't otherwise have access to arrow fend. Jotun woodsmen are a good example, as are EA Aby burning ones and Yomi Oni Generals (cheap enough to use in squads if you spam castles). Plus, of course, there's a decent number of spells air shield will help you out against in addition to lightning...