Here are my ideas.
When a character is "invulnerable" he/she will take damage but no knockback.
Mario -
Name: Mario Finale
Aura: standard fire aura
Attack: Mario's fists will set on fire, and then after 1.5 seconds he will project forward two immense fireballs moving like a double helix. The fireballs will expand vertically as they travel.
If the opponent is right in front of Mario, he/she will take up to 70% dmg, otherwise about 44%.
Pros: best ranged final in the game, good damage
Cons: slow, predictable
Aerial: yes, Mario slowly floats down while using it
Shieldable: yes, but will kill the shield after a while
Mario is vulnerable until he shoots the attack.
Origin: SSBB
Dk -
Name: Bongo Blast
Aura: standard fire aura
Attack: Donkey Kong will take out his bongos, and after about a second he will bang the drums sending four shockwaves alternatively left and right. Each shockwave deals 23%; you can maximise the effect by hitting the opponent with all shockwaves (92%) when he's right beside DK. It will star KO the opponent at about 150% dmg.
Pros: good range (a sound wave cover about 1/4 of Final Destination)
Cons: not very fast.
Aerial: yes, but DK will fall to the ground.
Shieldable: no
Dk is vulnerable when he's taking out his bongos.
Origin: DK 64
Luigi -
Name: Luigi Finale
Aura: green flames surround him
Attack: Luigi will take out his vacuum and suck anyone directly in front of him, trapping the opponent inside the vacuum. Then Luigi will say "here we goooo" in shaky voice, and hit the opponent with Thunder Hand, shooting the opponent alongside an immense green thunder towards the sky, and KO him/her instantly! If someone gets hit only by the thunder he/she will take 30% dmg.
After executing the attack Luigi will clutch his hand and howl in pain.
Pros: insta KO, very quick
Cons: worst ranged final smash in the game!
Aerial: no
Shieldable: yes, but kills the shield
Luigi is vulnerable when using the vacuum, so try to hit him before he hits you!
Origin: SSBB, Luigi's Mansion, Thunder Hand from the superstar rpgs
Fox -
Name: Mission Accomplished
Aura: standard
Attack: After a split second, Fox will dash forward as with a fox illusion (except with barrel roll animation). If he connects, he'll start hitting the opponent with several superfast kicks, dealing 15%; then he'll throw the opponent upwards, say "lock on!", his wrist device will flash and an Arwing passing by will pelt the opponent with a charged laser for additional 24% damage.
Pros: quite fast, good range.
Cons: shieldable, really poor damage for a final smash.
Aerial: yes, works also as a recovery move
Shieldable: yes
Fox is vulnerable while dashing, and while calling the Arwing.
Origin: SSBB
Ice Climbers -
Name: Nearly Absolute Zero
Aura: snow flakes around Popo and Nana
Attack: Popo's hammer will first glow blue; he will then track with his hammer a big glowing snowflake symbol towards the screen, and while tracking the last line he will slam his hammer on the floor. A snow storm of 1/2 the size of Final Destination will then form above Popo, raining ice.
The process takes 2 good seconds, and another 1.5 seconds to recover; however, you can command Nana in the meantime, to defend Popo!
This attack can deal up to 115% with both Climbers, 60% with one. Each snowflake deals 1%.
Pros: one of the most damaging final smashes in the game, defendable by Nana
Cons: shieldable, very slow
Aerial: No
Shieldable: Yes, but not for long
Popo is vulnerable until he hits the floor with the hammer.
Origin: SSBB
Samus -
Name: Omega Cannon
Aura: standard fire aura
Attack: On the ground, Samus will point her arm cannon forward, a golden halo will circle around her gun, and after a second she will shoot the very fast moving huge energy beam shown in the trailer; in the air, Samus will instead shoot a slow moving humongous ball of energy, which will explode by hitting something, damaging everyone around. The beam deals 70% and KO over 160%; being hit with the ball 86% and KO over 170%; the explosion 55%.
To balance the sheer power of this move, Samus will destroy her suit in the process (much like the omega cannon does in Hunters) and turn into Zero Suit Samus; however you can play as her by pressing "A" at the start of the match.
Pros: awesome range, great damage, good speed
Cons: Samus turns into ZSS
Aerial: yes, with different effect.
Shieldable: yes, but kills the shield, dodging it is a better idea
Samus is always vulnerable during the attack.
Origin: Metroid Prime Hunters
Zero Suit Samus -
Name: Crystal Flash
Aura: standard fire aura
Attack: Samus grabs a power bomb: instead of detonating it, she will instead absorb the energy of the explosion. While absorbing, she will float in a bubble of pinkish energy. You can control her flight with the control stick. You can hit the other characters with the bubble, dealing 12% damage and small knockback. After finishing, Samus will return with her suit back on. Heals 30% damage.
Pros: heals, doubles as recovery move
Cons: really poor damage, poor range, a bit slow
Aerial: yes
Shieldable: yes
Samus is vulnerable while detonating the bomb.
Origin: Super Metroid
Ness -
Name: PSI Rockin', Omega
Aura: blue aura with red eyes, evil grin on the face
Attack: Ness will slowly float upwards. After a second and half, he'll stop and three large hexagonal rings of blue, red and yellow energy will start rotating around him; those will damage everyone around him much like Zapdos does. After dealing damage, Ness will strike a "air guitar" pose, "play" an electric guitar sound and cause a spherical explosion of blue and red energy, of the size of Final Destination and then some. The rings deal 35% at most; the explosion will deal a random value of damage from 10% up to 120%, killing anyone over 130%!
Pros: great range, potentially the strongest final attack in the game
Cons: slow, predictable, can be weak
Aerial: yes
Shieldable: only the explosion, without problem
Ness is vulnerable until the rings are shown.
Origin: Earthbound
Meta-Knight -
Name: Master Tornado
Aura: dark energy aura
Attack: Meta Knight will slam his sword into the ground. This will spawn a dark whirlwind; this tornado will expand vertically while travelling forward at medium speed. Any character caught will be brought to the top of said tornado while taking damage. A trick for using it in arenas without pits; if used near the edge of the map it might bring the opponents over the barrier and KO them!
It will deal about 50% damage at most, at a rate of 2% per hit.
Pros: nice range, exploitable, quick
Cons: Meta Knight can be hit at any moment, not hard to avoid at first
Aerial: yes, if done in the air Meta will quickly fall down and use the move
Shieldable: no
Meta-Knight is always vulnerable during the attack.
Origin: Kirby's Adventure / Super Star
Peach -
Name: Rage
Aura: standard
Attack: Peach will get very mad and catch fire. She will then start to run or fly, dealing 28% damage and decent knockback to anyone she hits. You can change her direction or make her fly higher or lower with the control stick, but you can't stop her. Touching the ground in this state will cause a small earthquake in DK style. Lasts 6 secs.
Pros: very mobile
Cons: stoppable, range isn't great, damage has to be racked up, not hard to avoid
Aerial: yes
Shieldable: yes, two times in a row
Peach stops if at least 40% damage is dealt to her.
Origin: Super Princess Peach
What do you think?