For sure! He did come across as a lot less intelligent than he had proven himself in ALL of the prior VC up to that point, but there are legitimate reasons. Which I’m gonna lay out for you, under the cut, bc SPOILER ALERTS.
When you consider the larger picture: of the ocean of crap he’s waded through up until that point, we can’t just write him off as “crazy” or “dumb.“ He’s actually wounded in many ways, so his mind can’t be firing on all cylinders.
Not the least of which was the devastating betrayal of Louis and Marius, in their refusal to help him in his hour of need.

In IWTV he was an enigmatic tyrant, in TVL he partially corrected that by revealing his backstory and the vampire origin story and showed that he is a BAMF which means he CAN BE tyrannical sometimes,…
So if he comes across as such a disgusting moron, why share this story with us? Could be for the same reason he shared TVL: to correct the record, and to try to make some sense of it, get some closure, and maybe learn something from the experience as a whole. He’s sharing it with us so that maybe we can benefit, too, and as bizarre and as big a turn-off as it is, the very least you can take from it is the tried-and-true: “BE CAREFUL WHAT YOU WISH FOR – YOU JUST MIGHT GET IT” which seems to be a recurring theme for him, and in VC in general.
[Spoilers ahead…]
It’s in QOTD when we see him attempt to find himself a role in the modern era, that’s also when he appears to lose some of that quick wit we loved him for, as his new SJW GF wears him down, intending to destroy the fabric of society in the name of Extreme Social Justice. He can’t dissuade her from her plans, so he eventually just stops trying. He’s practically praying for Marius internally. She is manipulating him vigorously throughout their time together, keeping him sleep-deprived and physically addicted to her, arguing her philosophy irrationally, he’s constantly reminding the reader that he’s slipping, losing himself in her, he’s actually terrified into submission to her to the point where he doesn’t know where his loyalty lies when it finally comes down to choosing sides. He was not the one to save the day in that story. He watches passively as someone else does.
Akasha’s damage was done, a part of him has been crushed… it was a major blow to his sanity and his ability to be rational about things before leaping into action. In the beginning of TOBT he’s suffering already, haunted by his past. He is not healed emotionally, not in a position to make the kind of deal that he makes with RJ, and after that, he’s even less equipped, emotionally AND physically, to try to remedy the situation that HE CREATED.
The most devastating blow is probably when Louis and Marius both refuse to help him. At that point, he’s broken mentally from that betrayal, more physically weakened, and just grasping at straws to try to get things back to normal.
So is all that an excuse for the awful, terrible things he does in that story? Absolutely NOT. But you can see that he’s crippled in many ways, so his mind can’t be firing on all cylinders.