Here's a game:
You Are Sakurai Bias!
Pick 1 Smash Franchise (hell, it can be one that isn't in SSB yet if you want) and say how you would shamelessly cater to your own bias in Smash with content
My bias? Pokemon:
I would include three more Pokemon for Ultimate, a 3rd Gen, 5th Gen, and 7th Gen, and reveal them all in the same trailer
Pikachu's/Pichu's Side Special is now Volt Tackle (its much faster than Charizard's Flare Blitz, but does less damage and no recoil to itself)
Pikachu's/Pichu's Final Smash will be its Z-Move instead
Mewtwo's Shadow Ball damages as it charges
All of Pokemon Trainer's Pokemon will gain a 4th special; Pokemon Changing is now down by pressing A+B together
Even more stages including: Poke Floats, Tower of Mastery, Pokemon Battle Royal Ring, Battle Frontier Emerald, and Poketopia
Greninja in Ultimate is Smash 4 out-of-the-gate, pre-patched level (before the 20 nerfs and patches)
EDIT
Mewtwo is now a floaty, heavy character, at least as heavy as Samus.
Each of Pokemon Trainer's Pokemon also have their own Final Smash, instead of just doing one Triple Finish, giving players options before letting loose their FS.
Lucario has less startup and cooldown frames on its attacks as its Aura level increases.
Fire Emblem.
Current fighters are mostly unchanged.
New Characters
Hector: the first axe wielder in Smash and most popular character not represented in some way in Smash. He would be the slowest of all FE characters and one of the slowest in the entire roster, imagine Ganondorf but with an axe. However, to make up for that, his attacks hit REALLY hard and while not as far-reaching as swords, cover his hurtboxes to the point it's almost impossible to challenge one of his moves. Additionally, some of his moves produce lightbing hitboxes like Robin's DSmash, allowing him to reach further with those. His Down Special is Distant Counter: when countering, Hector will release a shockwave forward, allowing him to counter distant moves and projectiles. His Final Smash would be Thunder of Ostia, a powerful axe strike that summons a bolt of lightning on the opponent.
Ephraim: Another very popular character, Ephraim would be the first spear wielder in Smash. With balanced stats, he really shines in his disjoints. While not as big as the Belmonts', Ephraim spear attacks have more speed to them and are quite dangerous at the tip, his Forward Smash is comparable to Corrin's. His Final Smash is the Sacred Stone, where he seals his opponent inside the stone, KOing them instantly if above 100%.
Lyn: The most popular character not yet playable in Smash, she would be the fastest of all FE characters, though her overall damage potential is low and she would be incredibly easy to KO compared to the others... If you can even hit her, that is. Her Side Special, Quick Step, allows her to dash forward really fast or fake out the opponent and retreat back to safety. Her Final Smash is Winds of Sacae, where she cuts her opponent so quickly that it appears as if there were 5 of her attacking.
Veronica: FEH is a big success, that's no mistery to anyone, and Veronica is the closest it has to a mascot or face. Sure you have Alfonse and Sharena... but who really cares about them? Veronica would be a combination of a Dark Mage eith a Staff Wielder. Her normals would all focus on different spells and her Smash attacks would have her summon Chibi-Heroes to attack ala Pac-Man's Smash Attacks. Her specials would all use different status staves from the series, such as being able to disable an opponent's specials, freeze them in place or warp them right next to her. Her Final Smash is Tempest Trial, where she summons a tempest vortex in the stage to damage all opponents.
Echo Fighters:
Eliwood(Ike): Wielding the Blazing Blade, Durandal, Eliwood is the Lord that better fits Ike's moveset. His Up Special, however, is replaced with Roy's Up Special and all of his flame effects are red instead of blue. His Final Smash is Fire of Pherae, where he unleashes a series of fiery sword slashes on the opponent.
Anna(Hector): Based on her Heroes desigb, Anna would finally be included as Hector's Echo. Instead of Distant Counter, however, Anna gets a teleport move like Meta Knight's Dimensional Cape, thanks to her legendary weapon, Noatun. Her Final Smash is Open For Business! where she summons an army of Annas from the other games to unleash a final attack, family style.
Nephenee(Ephraim): There aren't many non-armored lance users on foot in FE, but out of all of them
I like Nephenee the most. Her Final Smash is Wrathful Luna, where she unleashes a single fiery strike at her opponent as the moon shines above, killing them instantly.
Joshua(Lyn): Joshua is the best Myrmidon and best FE character, these are the facts. His moves would have Ice effects added to them to better fit his sword, Audhulma. His Final Smash is the same as Lyn's, but is renamed as Winds of Jehanna.
Assist Trophies:
Camus: Camus would ride on his horse around the stage, attacking opponents with Gradivus while running over them.
Caeda: Caeda would fly around on her pegasus, occasionally flying down to attack. Don't try to jump, that's where she'll hit you the hardest.
Ninian: When summoned, Ninian will dance to her summoner, causing a random effect, either raising a stat of theirs(attack, speed, defense) or turning them invincible for a few seconds.
Nino: Nino will use Gronnblade when summoned, pining down an opponent in place and following with many other blades. Taunting near her will boost her attacks' power!
Takumi: Takumi will fire off wind arrows across the stage, he'll stand in place most of the time but he can still dodge and shoot you back at point blank. He can even clone himself to double the work, curious...
Stages:
Dragon's Gate: The stage of the final battle in FE7, the battle would take place in the first area of the map, with the Gate itself visible in the background and two locked rooms to the left and right edges of the stage, whose roofs work as platforms. Occasionally, some of the bosses that appeared in the original map will appear and attack the players. Lloyd and Linus will appear out of each room and each will perform a quick slash from one room to the other, Ursula will appear in the middle of the stage and summon bolt strikes from above, and Nergal will appear near the gate and summon black holes on certain parts of the stage.
Bosses
Grima: fought on Grima's Back, its hitbox is the shadowy Robin the head will try to protect. Grima will attack with its foul breath and summon dark spikes, alongside being able to summon Risen to fight you off.
Fire Dragons: fought on the Dragon's Gate, the Fire Dragons will stay each on one side of the screen, only ever moving their heads, their only active hurtbox, while releasing fire breaths or claw attacks. Be careful though as they hit hard, very hard.