I've tinkered a bit around d2dx, d2gl and reshade. Definetely can make something pretty clean. I'd favor d2gl + reshade because of the HD options and simple in-game settings menus. This might be long and i might've missed some things but that should cover most of what i've done to make it to work. Credits to everyone that have been working on marvelous addons and contributions to make this game look marvelous.
Step 1 : Fresh D2 install to get rid of all the other wrappers (I always keep a clean copy of the base D2, unless you know which files to remove)
Step 2 : Change Game.exe and Diablo II.exe -Compatibility- To Windows XP SP3 and Administrator
Step 3 : Download and Install the Median XL launcher, run as Administrator, follow the prompt to select your D2 folder and let it do it's things.
Step 4 : Get the attachment from
Here -Currently this is the fixed version provided by @pooque which enables HD Cursor and Font to work properly in TSW without crashing the game. Copy and overwrite those files into your D2 folder.
Step 5 : Go into the Launcher's Settings and change the Video Mode to 3DFX Glide and run the video test and confirm it's on 3dfx glide after the test finished. Close and re-open to confirm it's up to date. **PS: You can use directdraw, but i don't think Reshade will work.**
At this point you are done, you can play the game by launching it with the launcher, no need for fancy -3dfx in game.exe or anything else. Ctrl-O when the game launches, settings as required and game on.
(Optional) Step 6 : Follow the guide from @Zefir
Here -Get Reshade (google it) if you want to have customized side border in 4:3 otherwise you can keep the black side boxes or play stretched by using the Ctrl+O (from d2gl) after launching the game and putting the settings as you want. The game is in 4:3, so in full screen that are 16:9 you will have black borders.
(Optional) Step 7 : Install Reshade, follow the prompts by navigating to your D2 MXL folder and selecting your game.exe, then select OpenGL as the install option and the shaders you want. (the more you pick the longer it will load, I recommend trying the first 2-3 sets or all and then single out the ones you will use. **I've used personally used - Layer, Tonemap, Curves, HDR, and played with the sliders a little to my preference. You can always uninstall Reshade by running the install again and choosing uninstall. Just make sure you copy all the other files over everytime you do this in case the uninstaller removes some of them.
(Optional) Step 8 : Make sure you grab the
"DefaultPreset.ini" from 2nd Decorator and the layer.png of your liking, check in the other pages of @Zefir's there's a few nice ones.. that layer.png will need to be put inside the folder generated by Reshade as listed in @Zefir's guide. HOWEVER, I recommend going to an upscaller as suggested by @Lazerhawk
Here Upscale the picture to the highest, put it into paintnet and resize it to your desired windowed or fullscreen size, in my case i'm running the game on a 4k monitor in fullscreen, i resized the layer.png to 3840x2160.
(Optional) Step 9 : Once the game is launched, there's going to be all sort of things going on, first open d2gl with Ctrl+O and select your desired resolution and Apply the settings, open Reshade with "Home" and follow the instructions, once you get to the .fx tab. disable everything and enable Layer.fx, at the bottom, you should see an Edit global preprocessor definitions popping up, if not hit finish, switch tabs and come back. Under Layer.fx You want to change the LAYER_SIZE_X to your monitor size, in my case 3840 and hit enter, and do the same with the Y = 2160, and put the scale to 1.000.
Switch on and off the other .fx you want to play with and play with the sliders until you get what you want.
** The Reshade window can be opened with the "Home" key, the key can be changed afterwards if you want to use D2Stats, conflicting keybinds makes D2Stats take priority over Reshade, I changed mine to Insert and removed the Insert from D2Stats as i don't use the copy item text.**
My current monitor looks like this
Resized because forums doesn't like 4k pictures.
I hope this can help some of you and if anyone has to add anything or use any of this for guidance feel free! Happy hunting in 2.6.