In the Magic Trio:

England specializes in fae, sprites, and the magic of summoning and spiritual communication. He doesn't do well with spells, which is why he relies on artifacts (i.e. Busby's Chair, his spell book) and faeries to do that type of magic.

Norway specializes in enchantments and the elementals, more akin to wind. Most of the spells he uses are from himself, although he would use trolls and the like to assist his magic skill.

Romania specializes in charms, curses, and the art of potions. His Sight (the term fans dubbed as the ability to see fae) is relatively weak, which is why he isn't seen with them much.

If the three combine their skills, they can achieve stronger forms of magic; dimensional travel, widespread spells, and time travel are a few they can do.