Rain Flush (レインフラッシュ Rein Furasshu) is Toad Man's Special Weapon. It was originally created to cause rain for agricultural purposes, but the water was replaced with powerful chemicals to be used as a weapon against Mega Man in Mega Man 4. It fires a capsule into the sky, which then creates an acid rainstorm that covers a wide area and can't be avoided. The rain affects all things on the screen (provided they are vulnerable to it), including shielded enemies like Mets and Pakatto 24, and it can hit several times before disappearing. The weapon can hit Drill Man while he is underground and pierces Skull Man's Skull Barrier.
Rain Flush is Bright Man's weakness. Pharaoh Man and Skull Man are semi-weak to it as well. The weapon can be used as a substitute against Pharaoh Man if one has run out of Flash Stopper, though the player will have to contend with Pharaoh Man's speed. In Mega Man IV, Rain Flush can also extinguish the fire in Napalm Man's stage for a short time, and solidify the quicksand in Pharaoh Man's stage.
Damage data chart
Known damage values in units for Mega Man 4.
Bosses weak against Rain Flush
- Bright Man: Mega Man 4 and Mega Man IV
- Charge Man: Mega Man IV
- Wily Machine: Mega Man for the Sega Game Gear
Interestingly, both Toad Man and Mega Man use it in the form it takes as a usable weapon - firing a pod straight into the air, which then explodes and produces a cloud that releases the acid rain on targets below.
In the manga, Rain Flush is explained to be a two-step process. First it emits a spray of high-pressure liquid for environmental preparation, the liquid being a special ionized colloidal mixture. The resulting water vapor rapidly expands and reaches its freezing point in the atmosphere. In the second step, it sprinkles ice crystals into the forming clouds to force the development of rain. When Toad Man worked on farms, it had fertilizers and pesticides mixed into the rain, but after being modified for combat, it now creates acid rain.
Rain Flush appeared in the Rockman 4 manga.
- If Rain Flush is used on Dr. Wily as he escapes the first battle in Mega Man 4, he will be destroyed, and as a result Mega Man will be stuck in the stage, forcing the player to reset.
- The Rain Flush (followed by the Gravity Hold, Centaur Flash, Astro Crush, Lightning Bolt and Tornado Blow) is the first weapon in the Mega Man series to damage all enemies on screen regardless of defense.
- The "Flush" part of the weapon name may be derived from the Japanese word for shower (降らし furashi), so it can also be interpreted as "Rain Shower".
|Water Special Weapons and Techniques|
|Mega Man Classic series||Bubble Bomb • Bubble Lead • Rain Flush • Salt Water • Water Balloon • Water Shield • Water Shooter • Water Wave|
|Mega Man X series - X||Bubble Splash • Goo Shaver • Marine Tornado • Meteor Rain • Splash Laser|
|Mega Man X series - Axl||Splash Laser|
|Mega Man X series||Ensuizan • F-Splasher • Suiretsusen|
|Mega Man IV|
|Bright Man • Toad Man • Pharaoh Man • Ring Man |
Stone Man • Charge Man • Napalm Man • Crystal Man
|"Satellite Cannon" • Ballade • "Bridge" • Hunter • Wily Robo Iron Golem • "Wily Capsule"|
|Mega Man's Special Weapons|
|Flash Stopper • Rain Flush • Pharaoh Shot • Ring Boomerang|
Power Stone • Charge Kick • Napalm Bomb • Crystal Eye • Ballade Cracker
|Mega Man's support items|
|Rush Coil • Rush Jet • Beat|
|Damage Data Chart • Enemies • Script • Wily Station • Wily Battleship|
|Mega Man (Game Gear)|
|Bright Man • Stone Man • Star Man • Napalm Man • Wave Man • Toad Man • Dr. Wily|
|Mega Man's Weapons|
|Mega Buster • Flash Stopper • Power Stone • Star Crash • Napalm Bomb • Water Wave • Rain Flush|
|100 Watton • Apache Joe • Asteroid • B Bitter • Baby Metall • Bomb Thrown • Bounder • Changkey Maker • Dachone • Daidine • Dompan|
Gas • Giree • Gyotot • Hirarian 427 • Irucan • Jet Bomb • Lyric • Metall Cannon • Metall Mommy • Minoan • Mizzile • Mousubeil
Power Muscler • Puyoyon • Rackaser • Ratton • Rider Joe • Rock Thrown • Rolling Drill • Scworm • Sniper Armor • Space Metall
Springer • Swallown • Subeil • Sumatran • Taban • Tatepakkan • Teckyun • Tondeall • Toss Machine • Totem Polen
Twin Cannon • Yudon • V
|- Sub-bosses -|
|Escaroo • Octoper OA|
|Extra Life • Life Energy • Weapon Energy • Energy Tank • Mystery Tank|
|Battan • Bottomless Pit • Force Beam • Spikes • Mega Man (Game Gear) Damage Data Chart|