Heroes of Might and Magic III on iOS and Android.

There are many projects for the third installment that don't redraw the graphics. I haven't heard of Ubisoft taking any action against them. Maybe I'm just an amateur, but I've come to believe that under certain conditions, it's possible to achieve the desired result (original graphics) without infringing on anyone's rights.

You are mistaken; it is impossible to create a complete clone with the original graphics without violating copyright; if it were possible, they would have done it.

Added 8 minutes later

Are they not selling the rights? Or is there nothing to sell?
I heard that there are simply no source codes; they were supposedly lost when someone wanted to buy them.

In any case, the bottom line is that Ubisoft is not selling the rights. For example, I received a response stating that they are only developing the "Might and Magic" series themselves and are not involving third-party developers for this purpose. The third installment is not of great interest to them at the moment; they are more interested in developing online projects and older series.

There are two options: do nothing or do something, but in the current situation, the only way to do something is to change the graphics (of course, changing them just enough so as not to lose the original spirit and recognizability), as well as the game's title and the names within the game.