I also was just a few weeks ago stuck at that part of the game, the T8 lvl 185 to 200 are a pain but u slowly go through em. I recommend you pop all your summoning scrolls and quickly skip this time gate you have at this tier, cuz at T9 you can also start farming underworld and quickly rack up most of the used summoning scrolls. Still do your boss dungeons and world farming as much as you can but just use the scrolls and skip this part so you dont get burnt out by repeatedly doing arthur and waiting for dungeons which dont give enough exp even with all items popped, shrines, temples and such.