Char

Out of all the main girls, Kyoko is one of the veterans who has been fighting the longest, with Mami likely the only girl who fought for longer then her (this is excluding Homura’s numerous timelines, which technically would make her a veteran of about 8 years). In fact, it has been confirmed in Farewell Story that Kyoko fought for about a year before she began training under Mami, another very powerful magical girl. Given this CD takes place a year before the anime, it’s likely Kyoko has been a magical for at least 2 years. As most magical girls do not live for very long, Kyoko’s record is very impressive, especially considering the murder-suicide of her father and family would’ve caused many girls to witch out.

Kyoko has shown extreme resolve throughout her career, having been able to remain a magical girl even following her family’s deaths, her suppression/loss of her illusion magic, leaving Mami on rather poor terms, dealing with homelessness and a potential eating disorder, etc. What this has cost her however is the kind, selfless girl who wished to help her family, leading to her present self-preservation first philosophy.

Then of course, she meets Sayaka. Upon seeing her use her wish to protect others, Kyoko immediately fights her. This of course wasn’t out of malice, but out of a desire to seemingly protect Sayaka from the same path she went down. Tragically, Sayaka doesn’t accept what Kyoko says until it was far too late, and her very words are what set her down on a path to despair to become a witch.

Kyoko, having at this point developed a close relationship with both Madoka and Sayaka, the latter of whom began to give her a reason to fight for others again by attempting to save her from her transformation. Both Kyoko and Madoka are pushed onto saving her by Kyubey’s line about such not being done before. This, while technically true (Kyubey’s got a no lying claim to uphold) is deliberately manipulative to make Kyoko believe she can save Sayaka, which Kyubey even admits to Homura after the fight’s over.

Kyoko and Madoka go into Oktavia’s barrier and attempt to save her, with Madoka doing most of the talking as she’s known Sayaka for far longer and can’t protect the two from any attacks liks Kyoko can. This obviously doesn’t work - hell, Oktavia’s own witch description states that “Nothing will reach her anymore,” likely referring to Kyoko and Madoka’s pleas.

Homura eventually shows up when the situation is dire. Even with Kyoko’s severe injuries, with Homura as well as the fact her soul gem is still intact and able to heal her, the fight is survivable. However, she still believes she can at least help Sayaka in her death.

This, combined with her aforementioned suffering, the manipulative statements of Kyubey and the fact Sayaka for the first time in years became a person who reminded her for her original desire to help others as a magical girl, drives her to her unnecessary sacrifice. The nicest way to put it is that she decides she’ll put both herself and Sayaka out of their despair. Homura ultimately respects Kyoko’s request to protect Madoka - it’s very possible she’s experienced this situation before and/or knows Kyoko will likely resent her and not assist with Walpurgisnacht when she comes around, in other words meaning respecting Kyoko’s wishes is the best option.