What if you made his Side B into a move in which Ridley grabs the opponent with his feet and then, similar to Bowser's Side B from Melee and Project M, the player would choose how the attack ends? Bowser from Melee had the additional ability to bite a few times by pressing the B button before ending his attack in two different ways.
To begin, the Side B's start-up animation. On the ground, it could consist of Ridley lunging forward with his feet (slightly above the floor, due to his wings keeping him afloat, also dodging low-hit attacks from enemies), but in mid-air, it could be a sweep motion, exactly as what was seen in your showcase video at 5:50, but during the first few frames, it will grab on contact. Later frames could have Ridley scrapping the floor, damaging anyone nearby. As soon as the move connects, Ridley will be above the opponent at a 45 degree angle, holding the opponent with his feet waiting for the player's next input, but only for a few frames before the game does the default input on its own.
Now, what's the actual attack? Remember how Ridley from Super Metroid could grab Samus and, on rare occasions, he would immediately use one of 3 tail attacks before she'd be thrown away? These Super Metroid attacks, as well as other ideas, are shown and described below, along with suggestions on how they could work in Smash Bros gameplay:
This is the simplest attack Ridley uses. After grabbing with his feet, he simply lifts his tail before bringing it down on Samus to smack her on the back (or front, depending on what direction she was facing when grabbed) and send her flying. There was a variation of this attack in which Ridley would quickly smack Samus with his tail three times before loosening his grip, allowing the final hit to launch her. Contrary to the first variation, which used the tip of the tail to send her off, the triple hit variant consisted of Ridley using the underside of his tail (not the tip). In Smash Bros gameplay, after connecting the Side B (grabbing with feet), the player could simply tap B to make the tail hit the opponent (up to 3 times) before finally sending her flying towards the front.
If however, the optional B attack cannot be programmed, then the entire Side B's animation could simply consist of grabbing with his feet and
it automatically does either the single or triple hit. Regardless of the outcome, after the enemy is sent flying, he/she/it would be open for some follow-up attacks and, best of all, the end of this attack would leave Ridley in the air, where his superior mobility could allow him to catch up to his launched opponent for extra damage. Onto the next suggestion.
This attack in Super Metroid is Ridley spinning his tail at a ludicrous speed, making one or several full circle swings (clockwise or counter-clockwise), forming an anti-projectile ''shield'' around his body and hitting Samus if close. In Smash Bros, this could be a devastating kill move if Ridley were to successfully connect his side B move in the air above a pit, serving the same purpose as a Meteor Smash. When used above a floor, the opponent could bounce off the ground, allowing Ridley to follow up with the pogo-stick attack or etc. If the opponent has high damage percentage, the bounce effect would send him/her/it flying all the way to where Ridley was left at the end of the attack animation, giving him many more options to follow on.
If the optional tap-the-B-button can be implemented, Ridley would make his tail spin in a circle every time the button is pressed, thus hitting or slashing at the opponent while gripped in his feet, before the 3rd spin sends the enemy down. As a bonus, while the tail is spinning, it could destroy projectiles launched at Ridley or at his captured enemy (essentially, prevent someone from stealing his kill), though whether the spin gives him 360 degree protection or only protects his back is up to you. If the Meteor Smash idea is not desired, the final tail spin could send the opponent flying towards the front or back, depending on which direction the tail was spinning in
or what direction the joystick is held in, like Bowser's Side B ''finishers'' in Melee/Project M. Once again, if the optional B attack cannot be done, the Side B attack should consist of grab, automatic 2-3 circle tail spins and launch.
I am aware that you are making Ridley's up throw into a Maximum Spider/Wesker attack, with the end consisting of Ridley grabbing with his feet and crushing the target against the floor, as seen below
If, for whatever reason, you were to change the end of your Maximum Ridley attack into something else, this grab-and-stomp could instead consist as an end to Ridley's Side B. Whether its used on the ground or in the air, it would always be Ridley going up then down. If used above a pit however, Ridley would go straight down with his opponent,
killing both players. Since the opponent is under him, the first one to die would be the former, guaranteeing Ridley's victory if both are on their last stock. I personally think this is a deliciously cruel attack that suits Ridley as much as Ganondorf!
To sum it all up BaganSmashBros, if programming a Side B with multiple options is a no-go, any one of the attacks I've suggested above could serve as the definitive Side B attack by itself.
Or,
If it's actually possible, they can all act as ''finishers'' that players will be able to choose from after they connect with the Side B. Like Bowser, the finisher would depend on what direction the joystick (or button?) is being pressed.
Finally, if all the above suggestions are too complex to program or are simply not your cup of tea, then I present my final idea. The tail from Brawl.
Like in the boss fight, the tail would get the opponent ''stuck'' on it for the entire duration of the attack, building up their damage percentage and dragged across the floor. However, if used on the edge of a stage, Ridley could fall off, stuck in his animation until the attack ends (the move itself should last a second or less), without losing the ability to make a recovery of course. Any enemy grabbing onto the edge when the tail goes by will unavoidably get hit, though whether the opponent is sent down or sideways, I don't know. Perhaps Ridley could drag the enemy down with him till the attack ends?
I'd like to apologize for my long post BaganSmashBros. I'm simply ecstatic of how this Ridley mod is turning out to be, and unlike Nintendo and Sakurai, my opinions and suggestions, as well as all the fans', can reach you. Good luck and I wish you an early merry Christmas!