By other set I assume you meant the myth tomes set? I think darklight was bought with philosophy tomes when you last played, but those dont exist anymore. A good idea is to unlock your high and expert roulettes in duty finder. Myth tomes are uncapped now so you can easily farm myth to get ilvl90 gear, alongside binding coil of bahamut which you can do in duty finder now as often as you want. The new tomes (soldiery) have a weekly cap of 450 and you can use them to buy i100 gear which can be upgraded further.

There's the second tiers of CT (gives ilvl100 gear) and second coil (i110? I forget), while original CT doesnt have weekly loot lockouts now. Aside from that, there are extreme mode primals, relic quests have been expanded, and Frontlines (pvp) just came out. Many PVE players are getting into that, its a lot of fun and far easier than wolves den pvp.