when you hover over an item to see its stats look at the "Item Effects" at the bottom. Just hover your mouse over the little blue circle and it shows you what the effect is.

Equipping magical items do not increase your WOM, never did. They amplify your type of damage associated with the item you're wearing

Types are:

Holy
Magic
Fire
Light
Cold

Among others

So in my case, what I thought was WOM boosting, was plain magic boosting (same icon), and its amplifying whatever I do by "magic". The praying icon then would amplify whatever damage is caused by the holy magic school I assume. But does that mean my skeletons are stronger with it? If as a Vampire I'm relying on magic primarily to summon skeletons, then wearing anything magical is kind of a waste at lost opportunities for better protection armor, as I'm amplifying magic I'm not using?

Note: Not really finding the whisp thing very valueable yet... probably not using it right.

IMPORTANT NOTE: What an AMAZING mod. Not only is the graphical detail perhaps the best I've seen in Bannerlord... BUT you did something that ALL of the other mods and base game seriously and severely miss... there's NO game with them, it's just a sandbox. By incorporating lore AND lore-events you actually give the game - game, it's not just a big sandbox. I was just lamenting about how Bannerlord doesn't have anything outside its AMAZING sandbox, that Brytenwald and Vikings Conquest gave us an actual game. Great work!

No, it only affects damage spells, not summons