Wily 3 is a weird stage in that there are some sections that are really challenging to do optimally and can incur some brutal time losses, then there are other stretches that are a total breeze and feel more like waiting. How this stage is handled will impact how Wily 4 is handled and what sort of time loss you might be dealing with depending on how much risk you're taking.
Buffer your jump on spawn to get some free frames, then switch to Coil. Use Coil in the spot depicted below to avoid the first crusher. From there you'll re-summon Rush when the previous spawn disappears so you can mash down the second crusher. This will mean that Rush will once again respawn once you get near the screen transition, where you'll summon Rush once more to bounce from to get as high as you can before the transition without bonking the ceiling.

After this you'll float your way up to the top and avoid the balls along the way by mashing the buster as needed to move you. Avoiding damage is critical because the less health you have on the way to the end of the stage, the more you need to refill when using the M-tank, so damage should be avoided where possible. Make sure to grab the ladder as low as possible with the generous hitbox. You float slower than you climb so it's recommended to get climbing as soon as possible.
After the ladder jump make your way right, summon Rush to ready your buster to kill the gem in your way. Near the end of the hall is the spike jump as shown below. This can be a scary jumps and many runs have died to it. Some runners get through consistently no problem but some have lost paces to it. It's deceptive in terms of it's danger as a full jump will kill you and a low jump will as well. So you need to get comfortable with a mid-height jump to get across here. If you're ever uncertain or want the guarantee to get across, jump and back d-boost off of the gem above to lose a little bit of time but keep the run going.

After getting passed the spike jump, corner jump to the screen below, where you'll double corner jump and hug the right side of the left pit to get to the bottom screen. On this bottom screen you'll drop down and jump over the bottom shield enemy and make your way to the hall as shown below for a deceptively difficult strat that can cost a lot of time if not done correctly (10 seconds easily).

This hallway is really important to push for top times in this stage. The following things need to be considered and implemented for this to be effective:
- The spawning location as shown above is important as too much further ahead you will spawn the second Sniper Joe at the top, who will begin shooting, ruining the whole strat. Too far behind, you won't be able to bounce off of the coil to get up the ladder and you'll bonk the ceiling.
- Though you need to wait for Rush to summon, you'll want to hop on Rush quickly enough to avoid the first string of bullets from the Joe. If you feel you were too late on the spawn, wait out the firs shots but don't move forward and trigger the second Joe. Just wait in place and then go right after the bullets are clear as it'll be faster then trying to haphazardly put something else together. It's better to control a minimal time loss over hoping for the best.
- When you get up top the goal is to mash down the Joe as soon as possible so he doesn't shoot.
- From here, drop down and back d-boost off the Joe.
- Jump up the ladder, ladder jump, then go right, drop down the final ladder and make your way to the end, hoping as high as possible in the screen transition.
On the next screen summon Rush on the bottom so you can prepare to line yourself up to being in the spot shown below on the next screen.

The reason for this is because you get to hover all the way up unobstructed until the screen with the M-tank. The next screen you'll shoot so you can push yourself the the left wall and stay facing right.

When you get to the screen with the M-tank, you'll get grabbed and pulled right to the M-tank, at which time you'll be facing right, summon Rush and mash quickly to swing to the left. From there line yourself up with the ladder to get to the next screen.
The next stretch has two main ways to deal with it in terms of weapon use and you'll also be choosing where you'll use the M-tank on the swap too.
Weapons:
- Trident is the ideal weapon to use here as it uses the least amount of ammo between the two strats an allows for the earliest tank usage, but this is for high-level and is really dangerous done ideally.
- Tornado is much safer and easier but you use more ammo, which takes longer to refill with the M-tank depending on where it's used especially.
Tank usage:
- Ideally the tank is used between acquiring it and when you switch to trident because you combine the refill menu with the menu out to trident.
- If using tornado, it will be used at the end of the hall before you possibly have to d-boost off of the crusher so you have less health to refill, then swap to galaxy bomb while doing this menu - noting the that refill here and using tornado adds the extra menu and time to refill ammo.
- If going for the most amount of safety, particularly if worried about galaxy bomb and concrete ammo, use the tank after fighting Galaxy on the next stage, but this is a safety strat only, at high level this loses way too much time.
Only the trident strat will be covered, if you want to see how tornado can be use, check from this timestamped PB: here. Note that even if you need to slow a little here and there it will still be faster than either of the back up tank strats or tornado strat in general. A video showing the ideal trident strat can be found: here. The general idea is to shoot tridents at each enemy the moment possible. This is completely done by feel and comfort. Make your way to the door, either taking out the stomper or back d-boosting to get to the boss.
Colloquially known as the EZ Devil, this is a really challenging fight to get down initially, but is predictable and consistent once you become familiar with the one cycle kill. If you miss the one cycle and have to two cycle it costs approximately 25 seconds, so it's important to get this right. The picture for visual cues and the explanation will be found below, but a video tutorial from Polytopes can be found: here.

The picture above shows the approximate placements of each of the bombs and a base idea of how this can be done in one cycle vs five. Plant the bomb where the eye of the EZ Devil is and wait for it to get hit. The moment it registers damage, menu, then plant another bomb. When that damage registers, turn around and plant another and start walking forward at the same time. The hit box on the black hole is quite massive, so when the damage registers, menu again and plant the fourth bomb near the edge. When that hits, menu and then get ready to jump diagonally and plant the final bomb. This is much easier said than done and becomes more of a muscle memory, so keep pushing this on repeat until you feel consistent with it as each lost cycle is 25 seconds gone.