Hello,
I haven't confirmed with the devs yet, but I"m fairly certain that different ninjas just have different rarities/chances to skillbreak skills. Kisame's breakthrough is fairly powerful, so he falls into the "rare skillbreaks" category. Some ninjas' skillbreaks are easy to get, some are not, that's all.
Thanks!

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https://forum-narutoen.oasgames.com/page/show-post-22193-1.html

Madara [10 tails Jinchuriki]