User blog comment:B214/LN spoilers/@comment-26474856-20151106221714/@comment-1359322-20151116013337

Seriously you're comparing V8 Stella and V4 Stella. Stella after losing to Ouma went for a training session with Nene, it's obvious she would be back much stronger.

Also Stella had to nuked the entire arena they were fighting on before she manages to defeat Ouma.