Main, but there can by secondary too which doesnt affect anything, like achievements.

Right now, Light Party gets:

1) Lore
2) Scripture
3) Wolf marks
4) Ratings
5) Ranked Mount
6) Ranked Minion
7) Housing item
8) Fun
9) The Feast Achievements
10) Ranked achievements
11) Season vouchers
12) Fenrir pups

And custom match gets only

1) F U N.

Isn't that a little bit not fair?