[Ewierl]

Personally, I think their unique Pretenders could be a bit spruced up.

Mother of Tuathas is a good concept, and provides for lots of neat stealth-attack tricks, but is probably too expensive to be particularly useful; since her magic paths are generally what you need least as MA man, she's a one-trick pony.

Lord of the Forest compares unfavorably to the ubiquitous Great Mother: for 50 more base points, you get +1 to Nature magic, and save 30 points on new paths. (You also get more combat stats but lose trample and HP, probably a wash there.) Given that the base cost vs. +1N only balances out at N8, it takes a very specific build to make that chassis worthwhile.

(Divine Serpent is OK; I don't know anyone who uses it, but it's certainly good at what it does, stack up nature-only.)

My ideas:
1) Animal awe on the Lord of the Forest, as suggested above, or perhaps dominion-based Wolf summoning or the like.
2) A N/D pretender with residual Fomorian stuff, to match the new summons.
3) A lower-hp, physically smaller entity that is conceptually similar to the Mother of Tuathas. (Could be the same entity as #2)

I feel like there many possibilities for "an Avalon boost", but I want to hold my suggestions until I see what the new nations contain, both to find inspiration and avoid duplication.