If someone know this part, Please correct me if I am wrong.
As far as I can remember, the BUG has something to do with whatever thing he wants to get to MCs location.
They will of course will success to get the 'curtain used in bed' (I'm not sure what it call, but once that thing is destroyed, the barrier will open and some flowers will witted). They successfully got this thing (If I am correct, it should be a token of love (?)) because of fire, I mean,the area is burned because the BUG talked with the girl who is always in the side of MC (there is a teenage girl which is serving MC). The girl thought that once the BUG get the curtain, the love between the BUG and MC will once again bloom or something like that.
When the barrier open, the BUG of course is not interested with an old lady and immediately went to a place he wanted to go. I can't remember how and what happened here but they fight I think and MC successfully get the inheritance which the BUG wanted and the thing is actually a sacred place(?) or palace(?) where there is so many sacred weapon.
That sacred palace was owned before by a certain or legendary hero(?).
Since that sacred place was owned or MC can only open that place, MC became an elder of a certain sect which the BUG is also an elder.
Fast forward.
The legend has something to do with the owner of that place and a certain lady which the BUG wanted to reincarnate. I think, once that lady successfully reincarnated, the world will start the destruction (please correct me if I got this wrong) but MC prevented it before it happens.
MC made more weapons which is higher grade than the weapon that can be found in the sacred place.
There are many sort of scheme regarding the sacred place (they wanted to kick out MC being n elder of the sect and owner of the sacred place) since they know the secret behind the sacred place (I can't recall what happened about this and even the fight against the lady, you can wait for others spoiler or the translation) but MC told them that most of those weapon is her creation. At first they doubt it but when MC prove it in front of them, they eventually believe her. So, the scheme against her failed.