Returning to PSO2 for Episode 4.

[ArataWata]

I haven't played PSO2 since Episode 3 which I dabbled a bit with and with all the changes, news features and even a new class added into the game since then with Episode 4 I'm pretty clueless to what I'm supposed to be doing.

I know grinding is going to be my main goal but what should I be grinding for?

What's the end game like, what sets of gear should I be aiming for?

Are there any viable class build guides out around anymore?

[Spiral]

I haven't played PSO2 since Episode 3 which I dabbled a bit with and with all the changes, news features and even a new class added into the game since then with Episode 4 I'm pretty clueless to what I'm supposed to be doing.

I know grinding is going to be my main goal but what should I be grinding for?

What's the end game like, what sets of gear should I be aiming for?

Are there any viable class build guides out around anymore?

Arguably, most of the end game/class builds/unit gear is pretty much the same.

Gear wise, there are a few more unit options (saikis are still commonly used) now, many new 13*'s and much easier methods of working towards them, and the addition of skill rings (only real use for gathering) which add on extra abilities. If was playing when aust was a thing, aust is still best weapon for most weapon types.
Many newer weapons ("new types") now use a new grinding system which is much easier/cheaper to work with than the previous.
Also new is collection files offered by pudding (hands out extreme quest passes, next to coffee) which make it easy to work towards future weapons, amongst other options.
With more affix options and quantity, affixing has been simpler (especially if played before +40%'s were added in ep3) and it is more possible to cheaply get more effective setups.

Class wise, a few skills have been added, but builds generally remain the same - most merely having new skills added in. Similarly, some PA/tech customizations added. (And all of ep3 kuron PA's if played before that)
New class "summoner's" skill line is fairly linear and simplistic. With new class, "pets" replace weapons, but must be worked on like weapons to be effective. (Instead of grinding/max element/affixing weapons, max leveling/candy box optimization)

As for what you should be aiming for, would depend on situation. If already 75 and had a respectable setup, focus on picking out a pair of skill rings and looking at collection files/guest character CO's for nicer weapons. If pre-75, likely should focus on leveling. Note that, added in ep4, completing daily "featured quests" hand out randomized gifts, possibly netting bonus quest tickets for practically free levels through "bonus quests," so do those if needing to level.

Hopefully that makes some sense!