My ears are shot and that is nice dreamcast era audio but sounded clear enough to me, that said I do fairly well with accents so maybe it is that.
It appears I was somewhat late for the show
I wanted to try you out myself puny gaijun (don't know if that is an in game term or corruption of gaijin -- later in your transcription the girl refers to the main character as Gutsu so something Japanese is possibly shining through.)
but I don't need the ? to be come human and defeat you.
? is something like hawks. Don't know their context within this game or if there is some similar sound alike (many demons needing magical items/entities/groups to be called forth in folklore -- and if they are playing with shrieking mandrakes at the time position of the video linked then guess we are dealing with folklore, and those guys in tabards and what could be bird masks could well be such a group but I am not inclined to watch it* to find out).
*did always used to see several copies of it it for £8 in the game shop after the Dreamcast had died and wondered about it. Looking at current prices it is not my worst "if I had the money and space I would have" but could have done something.
Is that 1:38:06 in the first video or the second? Same character is speaking as from the stuff above so I will assume so.
Starting at 1:37:58 in the first video (end of boss fight)
You've got stronger branded one. Impressive!
[What's stopping you I'm still alive]
Hah that is enough for today.
We both have other things to do for now.
Before you and I can savour the sweet flesh of death. [odd phrasing that one, release of death or mercy of death or company of death being what I normally expect, but more or less in the stock evil speech thing and I don't know what role flesh plays in this game or that character's conception of reality]
We must remove the small bone which impede us. [bone might be bow but that makes even less sense, and bone barely makes any, but if talking about flesh above then bone is probably a more fitting thing]
You better hurry; the land of good is in trouble. [good sounded more like goern so if it is a place name in the game then maybe do that]
[deep rumbling hmm and evil laugh as flying off.]