My fav part of the game used to be duels, then duels got butchered with changes to dueling formula and duel motivation, most of the old school duelers quit and it became a pure P2W contest who has a higher lvl of the gear and weapons. Nowadays, I only duel for quests and events and can still beat purely skilled duelers just with the gear bonus (says a lot about modern dueling).
I also got into the battles before V2 started. This used to be the most fun part of the game, different tactics, interaction with other players, even the rewards used to be quite decent (before the clicky events got introduced which made bonds from battles kinda obsolete). But since most of the servers have battle numbers now which are more like maneuvers in the old days (except for C, A and M worlds), I rarely join, except for occasional Awesomia fight and such.
I rarely do quests (only for AP/SP) and I never got into adventures due to toxic chats/ broken game mechanics so the only reason I´m still around is to stay in touch with old friends and doing occasional duel/FF in between the hours of church building.