I found 3 Touhou Doom WADs. They are known as Basement, Garden, and Tower (most creative names ever 2014).
Basement is, what you probably would expect, Flandre's basement, though it's not even close to big. You fight Flandre, and you are supplied with Super Shotguns, BFG9000s, Chainguns, Soulspheres, Megaspheres, and a crap-ton of ammo. You might think it's hard, and it somewhat is. In reality, all Flandre does is shoot powerful plasma projectiles at you (which are very easy to dodge), and instakills you on melee. She's also pretty darn fast, so have fun hitting her with BFGs. The room isn't very detailed, and there's supposed to be a mirror but it seems to glitch out and gives me a Hall Of Mirrors effect. Not the most exciting battle I've experienced.
Garden is Yuuka's garden... if you consider a maze a garden. Yuuka's "house" is a shack with a BFG9000, Blue Armor, Soulsphere, and Megasphere. You also get a Super Shotgun (which you WILL need) and a Chaingun (which is pretty much useless, Yuuka's painchance (how often an enemy reacts to pain) is REALLY low). Now onto Yuuka herself... She's slow. Probably slower than a normal Doom Zombie. She has a huge amount of health, and when she attacks, she throws 3 BFG9000 projectiles at you, which is pretty much an instakill, even with full 200 health and 200 armor. Yuuka can go into the maze, but it really makes her a lot less threatening since you have many walls to hide behind. If she was faster (say near as fast as a Pinky Demon or something), then running around in the maze with Yuuka would be pretty scary. This battle could've had potential.
Tower is where you fight Alice. This battle is pretty damn hard if you don't conserve ammo. There's a platform in the middle of the room that raises down, and the platform has a BFG9000 and some ammo on it. You also get a Super Shotgun and a Chaingun. There's also only two Megaspheres, and you will need them. Alice can fly, spawn dolls (which are 10 times more annoying than Lost Souls, these things throw projectiles at you and use a strong melee attack), and she has a considerably low amount of health. This map gives you virtually no cover at all, so you'll be running. A lot. It's pretty funny when the dolls actually start to fight each other, and even fight Alice (talk about bad parenting). If Alice actually attacked instead of spawning dolls everywhere, she would be a pretty reasonable boss character.
Here's a video showing off these 3 WADs, download links for them are in the description:
https://www.youtube.com/watch?v=ycspoJfPWOsYou know, I kinda feel like seeing how strong some of these characters are against other very powerful Doom Monsters. Cyberdemons versus Alice, anyone? Maybe even seeing how long they can last fighting the Icon of Sin? Possibilities are near endless.