I have good ideas for the Pvp system in Tree of Savior that will allow you to play with friends and make the Pvp more competitive and enjoyable 
I would recommend having two separate searches for Pvp. A casual Pvp match seach that you can queue up for and search for a party alone or with friends (5v5, 3v3 and 2v2) Winning games in this queue would reward a Pvp currency that you can use to buy Pvp gear that is optimized for end game Pvp. The other search would be a search that you can que for after making a ranked Pvp team with another player(s) that you have met in the game or are friends with also offering 5v5, 3v3 and 2v2 game modes. Rewards for this queue would be ranking points for winning. There would be 5v5, 3v3 and 2v2 rankings 
These changes to the game would add the ability to make team comps based on classes that work well together. It would also give you team comp practice and gear progression in the casual mode. I believe that these changes would make your game one of the top games in the world. The profits from cosmetics and tokens etc would go way up and there would be way more players. Good job on making the game not pay to win and keep up the good work 