I just solo'd Sakurajima depths(lvl18) including Tiamat and Momotaro without using my npc party members(because they where all used up from grinding) at level 11 and managed a SS ranking.
...not sure if this game is way too easy or I'm just good...
What do you guys think?

Tiamat isn't that hard on solo and Momo dies in about 2 hits on solo o:
If you can do the higher level dungeons without a problem then I think you're pretty good o/ (Or I just seriously suck)

Wrong sub-forum.
Please try to post in the appropriate sub-forum next time.