I can see Leon Kennedy's final smash be a few powerful shots from the rocket launcher he uses at the end of Res4. (They could even have Ada throw down to him)
But, of course, if they have Leon they must have Chris and his final smash would be the satellite laser he uses to destroy the giant uroboros monster on the ship in Res5.
Please, Godkarmachine (Who is behind me, and invisible...I looked
) explain this moveset you have imagined.
First of all thanks for the interest xD
Well umm they would be...
Megaman
-Up smash: Black hole (megaman V game boy)
-Side smash: Some generic force shield attack like the one Megaman Volnutt uses in tatsunoko vs capcom with his shield arm
-Down smash: Commando bomb (megaman 10, its shockwaves fit just perfectly)
-Up strong: can be a kick like the up strong of snake in brawl or Megaman Volnutt's down/forward + strong attack kick from TvsC
-side strong: slash claw (megaman 7)
-down strong: Some generic kick, every character has it xD
-Dash attack: dash xD (or charge kick from megaman 5 as it does the same thing)
-Air neutral: top spin (megaman 3)(even if it sucks in the actual game xD)
-Air forward: could be a punch with the buster or a blast with the buster, meteor smash like the one mario has
-Air backwards: backwards kick (like fox, falco and wolf)
-Air down: a buster blast (like Ivysaur's aerial downward)
-simple a would be the weak combo like everyone else
-B: mega buster (of course), can charge it while walking but can't use other special moves while charging
-side B: could be any weapon (maybe quick boomerang, metal blade, electric beam, etc...)
-down B: Jewel satellite (megaman 9) can be used te reflect attacks like fox and falco's reflector
-up B: rush coil
-Grabbing would be with thunder claw from megaman 8
-Final Smash: Weapon Overdrive (He starts to shoot a barrage of special weapons)
Megaman X
-Up smash: Rising fire (megaman X4)
-Side smash: Spinning Blade (megaman X3, shoots two razor discs)
-Down smash: Melt creeper (megaman X8, two rows of fire go to each side)
-strong side: Z Saber (as he uses it in megaman X6)
-Strong up: Like the one for megaman
-strong down: like the one for megaman xD
-dash attack: soul body (a clone of X appears in front of you damaging the enemy)
-Air neutral: triad thunder (three electric balls appear surrounding you)
-the rest of aerials would be like the ones for megaman
-B: X buster, can be charged twice
-side B: Like megaman's one, can be any weapon
-up B: Nova strike, similar to fire fox or fire bird (fox and falco)
-down B: rolling shield, absorbs attacks
-grab attack is regular
-Final Smash: Seraph Form (Like the final boss from Megaman Zero)
Zero
-Up Smash: Shoenzan (zero slashes upwards with a fire saber)
-Side smash: Charged saber attack from Megaman Zero series
-Down Smash: Earth gaizer (Zero punches the ground making it explode from both sides)
-Up strong: Up slash
-Side strong: Saber combo (three hits, like the one in Megaman X4, X5)
-Down Strong: Kick
-Dash attack: Shipuuga (Zero waves his saber in a quick way)
-Simple A would be the saber combo from Megaman Zero series (three hits)
-Air neutral: Kuuenzan (rolling saber slash)
-Air forward: Saber slash (like Ike's)
-Air backwards: Saber slash (like ike's)
-Air downward: Hyouretsuzan (falls to the ground with an ice saber, similar to Link's down thrust)
-B: Zero Buster
-side B: Raikousen (like fox and falco's side B, Zero teleports stabbing with an electric saber and leaving a thunder in his path)
-down B: Ensuizan (Zero does a rapid rolling slash)
-up B: Ryuenjin (similar to marth's up b, Zero rises with a fire saber)
-Grabbing With the chain rod from Megaman Zero 2
-Final Smash: genmurei (shots three giant crescent shaped waves from his saber that instant KO anyone who is struck)
About the M-rated characters... Snake is from a M-rated game and he appeared in Brawl so I see no problem with others