Sakurai has reveled that about 1.8 voted where casted and he goes into detail on why the last 3 characters made it it.
Source
It sounds like the team really wanted to do Corrin and it sounds like they used every last minute of the DLC contract.
Source Gaming wrote:Cloud
Having a representative from Final Fantasy is an amazing feat! And the character that was the overwhelming favorite among the cast of Final Fantasy was Cloud. Wielding his massive Buster Sword with ease in one hand, he has speed, reach, and power. If left unadjusted, he’d definitely be overpowered. After thinking about how I would approach this character, I decided his swordsmanship style would utilize the concept of “swinging through,” which is exemplified in his forward smash. This move has Cloud build up some power before swing three times at high speed. It maintains his speed and reach, but is balanced by having a window of vulnerability before the attack. And he’s fast, but his recovery is weak.
In addition, to add a system that is Final Fantasy VII-esque, we’ve implemented “Limit Breaks.” When the Limit Break gauge is full, you can unleash one extra powerful version of one of his special moves. The tides of battle can swing based on these Limit Breaks, so it’s a unique mechanic that both Cloud and his opponent will need to keep in mind.
Corrin
After internal analysis, we decided that if we’re going to make DLC, we would choose a character from a soon-to-be-released new game. After consulting many times with Nintendo and looking at the upcoming release schedule, Fire Emblem Fates was in just the right spot. It’s already been released in Japan, but is yet to be released overseas, making it a prime candidate in terms of timing. I personally felt that having too many Fire Emblem characters was a problem, but after talking it over with the development staff and discussing logistics, I felt certain that I could make them a fun character.
Corrin has an ability called the “Dragon Fang,” an ability that lets them shapeshift into a dragon. Other than transforming their body into a dragon, they can transform parts of themselves, turning their arm into a spear, or into a beast’s fangs.
In Smash 4, Corrin has become a fighter with very long reach. Saying they’re similar to Dhalsim would be too much, but they can unleash smash attacks from an unreachable distance for other characters. Also, their side special move, where they can stab into the ground and pin themselves and/or their opponent there. This is a type of move that has never before appeared in Smash.
Bayonetta
We were conducting a “Smash Ballot” where people could vote for their favorite characters. Worldwide, 1.8 million votes were counted, and of the fighters that were negotiable, as well as realizable in Smash, Bayonetta had the highest amount of votes!* Bayonetta 2 was also a Nintendo exclusive, so negotiations were very easy.
*TL note: In case “negotiably possible” isn’t clear, Sakurai uses the word “negotiation” here, so I take that to mean negotiations in a business sense. As for realizable, Sakurai has written about that before, in column 430.
But because her original series is so distinctive, I was very troubled, trying to think of ways to properly represent her. In the end, I made her a combo-heavy fighter that can start combos from various places. Because you need to think about how much knockback to deal if you want to begin a combo, she’s a fighter with a lot of depth.
She has many moves that show off her distinctive character, like Wicked Weaves, which uses her hair as a conduit to summon forth limbs of Infernal Demons, or Witch Time, where she must predict her opponent’s offense to counterattack, creating an opportunity by slowing time.
To tell the truth…Going through the ratings board for each country/region was extremely difficult. In particular, Japan’s rating board was very strict on Bayonetta’s sexy antics, and there were many times where I thought “You’re not even going to let this through?”
This batch of DLC fighters took more work than the fighters in the base game, and they all have their own especially unique characteristics and playstyles. Knowing this is the final update, I put in as much effort as I could, so please enjoy!
Image Caption:
Smash Ballot
A website where people could vote for the characters they would like to see as playable fighters in Smash. Starting in April 2015 and ending in October of the same year, we collected approximately 1.8 million votes worldwide (after removing blatantly duplicated or repeated votes).
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It sounds like the team really wanted to do Corrin and it sounds like they used every last minute of the DLC contract.