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for ongoing cleanup projects.
Agreed with removing that redirect. It has 50 wicks as well, so it does seem like it's harmful if it's misused.
Currently mostly inactive. An incremental game I tested: https://galaxy.click/play/176 (Gods Of Incremental)^ - Something like Decoy Protagonist.
Disambig Needed: Help with those issues! tvtropes.org/pmwiki/posts.php?discussion=13324299140A37493800&page=24#comment-576If we ever turn it into new trope, I think more generic name like Mid Season Second Hero might be better.
Back to the issue at hand, is it ok to put the redirect on cut list now? I will later clean up Kamen Rider folder in Sixth Ranger.
You really should clean the wicks before putting it on the Cut List. https://tvtropes.org/pmwiki/relatedsearch.php?term=Main/SecondRider
As someone who works on that section from time to time, I looked at it more critically, and... yeah, it needs work. Even setting aside some ZCEs that need elaboration, most entries don't highlight that the "Second Riders" really are new characters introduced to the cast, even if they take their time joining the heroes' side (almost all do eventually). I may take a pass at rewriting the intro to better focus on that aspect.
But regarding the redirect, I have no issue cutting it.
No, it's largely an informal Fan Nickname. As is "Sixth Ranger" itself, actually.
I went ahead with rewriting the intro. I'm open to suggestions for improvements.

Second Rider
The problem is that people link to it instead of Sixth Ranger and is clearly misused.
Sixth Ranger is "A later addition to an already-established Team." (from laconic page), but Second Rider is mostly "The series usually starts with a lone hero and his supporting cast, but then a third of the way through the show a second Rider with a different set of gear will appear." (from Kamen Rider folder in Sixth Ranger) which is dubious. Still, that might worth discussion as I can see it being the case of Tropes Are Flexible (a little too much though), Downplayed Trope, or maybe even worthy of new trope.
The truly bad case of Second Rider examples are when they list someone who was there from the beginning so it's just plain wrong. It doesn't help that Second Rider is actual term used by Toei and many are indeed being there from the beginning.
In short, I think the redirect only cause confusion.