Posted August 31, 2023

1) the video:
I followed the link, but they wanted me to pay a "subscription" fee to access files. No thanks.
2) Reshade
As far as I understand it, Reshade provides the technical interface for adding shaders to old games.
The shaders themselves must be programmed specifically for every game. There is a long list of "presets" uploaded by users. I'm astonished by the sheer number of presets already submitted. Yes, Gothic 1, 2 and 3 are among them too.
BUT, one doesn't know how good these shaders are. Don't expect too much, because programming them isn't trivial. Minecraft shaders needed years of work to become stable enough. Fixing graphical glitches (flickering, black surfaces) and unbalanced effects (like overly bright highlights and bloom etc) takes time.
3) texture packs for Gothic 2
No idea, sorry. I'm always hesitant to change textures in a game because that might alter its style and "feeling".
Good luck!