This isn't about character power levels, it's about the recent voting battle, which Ninian beasted with an almost 10-to-1 voter margin against basically every opponent.
... Which was great for me! Non-stop bonus votes meant I got non-stop 3-7 times the normal score! I was in 3,542nd place, for a grand total of about 9,000 feathers without ever needing to actually be on a winning team! (Thanks to bonus voting, being on the more popular character's team is a sucker's game. Thanks to the chance of a come-from-behind victory by a well-timed bonus, more popular characters lose about 1 time out of 3, like Boy!Corrin beating Loli!Tiki before being summarily eaten alive by Ninian. Better to back a loser with tons of bonuses and occasionally get surprised with a win than to occasionally eat losses in overall score backing a should-be-winner that ultimately loses and get nothing for it.) If I'd just saved more feathers for the end of the bracket (with 7x bonuses) instead of burning them early in the first bracket (3x bonuses), thinking it was like previous rounds with limited opportunities to actually get the bonus, I could have gotten into the top 1000...