I’ve played the game before but I quit because of time, I quit almost at the end of April 2017. But I’m thinking of comeback but wanna know:
a) how is the state of game now? what have changed in all this time?
b) are the classes more equilibrate now?
c) what things should i know right now ?
d) any advice?
first you need to read this thread
Clarify which year too.
try reading the news page from the time you stopped playing up to now to get a clear perspective of the changes and updates…
end of April 2017 updates:
https://treeofsavior.com/page/news/index.php?n=24
now most of ppl just waiting for new r9 patch 
game is better now imo but its just my personal opinion ;3
Thanks 
Sorry i quit this year 2017
So for you, lots of stuff changed.
Entire rebalancing, DPK removal, WB revamp.
Yeah just dig around the patches after May and look at times. If the time taken for maintenance is more than 4-5 hours, read that patch.
Also you missed some nice bugs and ninja changes (eg. PD2) which arent mentioned in any patch