User blog comment:Linathan/Unit Spotlight: Demonic Idol Kikuri/@comment-26053138-20150423175608/@comment-26140304-20150423215325

Overall, I believe that Kikuri and Diana serve different purposes. Kikuri's "BB regen when attacked" buff is the best in the game for SBB as it increases BB gauges by 5-7 BC. Diana does a better at BB regeneration as she increases BB when attacked and when your turn ends with her SBB. She also has the "BB regen when attacked" effect on her Leader Skill.

Both units are very great subs too. They both perform very well with their own abilities. Here are some more comparisons to make here:
 * Kikuri has better stats, given that her Extra Skill is activated.
 * Kikuri has one of the highest-ranking Drop Checks in the game on her SBB. Kikuri has a 44 BC Drop Check compared to Diana's 18 BC Drop Check. This may not pertain to what you want to know, but it's a pretty significant difference.
 * Kikuri's "BB regen when attacked" buff is the best in the game, making it much easier to fill BB gauges, especially in Raid and Trials.
 * Kikuri's SBB damage modifier is 550% compared to Diana's SBB damage modifier of 500%.

Personally, in terms of leads, I would use Diana if I don't believe that my team can get BB every turn. Otherwise, I would choose Kikuri as a lead since her BB fill rate is as good as Ares' Excelsior and it has a nice bonus in boosting Dark type Atk by 100%. :)