All the Robot Masters from MM2-10. (Except the Robot Masters from Mega Man 9 as the Robot Masters in that game and the first game were built by Dr. Light, but were reprogrammed by Dr. Wily. After their defeat they were brought back to normal.)
DWN. 009 Metal Man
DWN. 010 Air Man
DWN. 011 Bubble Man
DWN. 012 Quick Man
DWN. 013 Crash Man
DWN. 014 Flash Man
DWN. 015 Heat Man
DWN. 016 Wood Man
DWN. 017 Needle Man
DWN. 018 Magnet Man
DWN. 019 Gemini Man
DWN. 020 Hard Man
DWN. 021 Top Man
DWN. 022 Snake Man
DWN. 023 Spark Man
DWN. 024 Shadow Man
DWN. 025 Bright Man
DWN. 026 Toad Man
DWN. 027 Drill Man
DWN. 028 Pharaoh Man
DWN. 029 Ring Man
DWN. 030 Dust Man
DWN. 031 Dive Man
DWN. 032 Skull Man
DWN. 033 Gravity Man
DWN. 034 Wave Man
DWN. 035 Stone Man
DWN. 036 Gyro Man
DWN. 037 Star Man
DWN. 038 Charge Man
DWN. 039 Napalm Man
DWN. 040 Crystal Man
DWN. 041 Blizzard Man
DWN. 042 Centaur Man
DWN. 043 Flame Man
DWN. 044 Knight Man
DWN. 045 Plant Man
DWN. 046 Tomahawk Man
DWN. 047 Wind Man
DWN. 048 Yamato Man
DWN. 049 Freeze Man
DWN. 050 Junk Man
DWN. 051 Burst Man
DWN. 052 Cloud Man
DWN. 053 Spring Man
DWN. 054 Slash Man
DWN. 055 Shade Man
DWN. 056 Turbo Man
WN. 057 Tengu Man
DWN. 058 Astro Man
DWN. 059 Sword Man
DWN. 060 Clown Man
DWN. 061 Search Man
DWN. 062 Frost Man
DWN. 063 Grenade Man
DWN. 064 Aqua Man
DWN. 073 Blade Man
DWN. 074 Pump Man
DWN. 075 Commando Man
DWN. 076 Chill Man
DWN. 077 Sheep Man
DWN. 078 Strike Man
DWN. 079 Nitro Man
DWN. 080 Solar Man
Sorry about not listing their powers and all, it would have taken forever if I did that. Also you can easily look up each Robot Master on the Mega Man Wiki.
Yea, well yellow devil is a more annoying version of shadow devil based on what I gathered. You can only ever get one hit at a time before he magically depixelates and then repixelates only so that you can get your next hit before he starts this fun process over again.
Yea Yellow Devil was annoying, but in the first game there was a glitch that made him way to easy. Also you have it a bit turned around. Yellow Devil isn't a form of the Shadow Devil as the Shadow Devil appeared in the X series which took place a good few hundred of years or so after the classic series. So the Shadow Devil is a version of the Yellow Devil, the Shadow Devil is a basically the Yellow Devil on steroids. Also the Shadow Devil has a bit more unpredictable pattern and moves making him more annoying (one of his moves is literally impossible to dodge unless you have really, really good reflexes. The Shadow Devil splits into 2 halves (16 squares in total of the black goo he is made out) of on each side of the screen (8 on each side) then pieces start flying at you randomly making him much more annoying. Also in this RP Wily put some of the traits of the Shadow Devil and the Green Devil into the Shadow Devil to make it stronger.