Are the "HD" graphics available somewhere for MM6? They link on GrayFace site is dead.
Did you look further down the page? There's another option named "Resolution Mod for MM6". It's a link to another site: https://sites.google.com/site/angelddeath/#TOC-Might-Magic-6-resolution-mod
However, be sure to read the paragraph before the link on the "GrayFace Homepage". Here it is for convenient reference:
Mods by Angel Death that make the game scale in windowed mode to the desired resolution.
To use them with my patch, create ExeMods subfolder inside the game folder and put the DLL there.
There is a similar message of instructions in two languages with the file, but not as elaborate.
Admittedly, that's likely not going to improve the appearance, but instead provide a resizable window to fit the whole screen.
I haven't gotten around to trying this myself…