Hi!! thanks for your feedback!
Second floor has three stone gates then a seal gate before reaching the next level.
- For the first stone gate, you must first defeat the lamia keeper
- For the second stone gate you need to find a key in the sucubus throne and complete the 5 statues puzzle (target their sensitive spots)
- For the third gate you need to cross to the mirrored dungeon, and find clues in the mimic chests, and deal with teh succubus in the throne room
- for the seal, you need to defeat Kagura (chapter 3) in the snowy region in the north map, then come back to break through the seal.
All seals will require you to complete a chapter and defeat a boss ^^
There is also a walkthrough here
There's also a support channel in Discord Kun Server
Hope it helps. If you find some bug please report and will fix it asap :D
⭐Happy New Year!