User blog comment:MiraMajin/Elfman's True Power/@comment-219.89.149.251-20140225040710

Elfman did a TO on that beast, tho it was never stated whether he did so in order to protect his sisters.

It could've been that Elfman just rushed at the beast, did TO and thus left Mira unable to go all-out on the beast due to the risk of causing permanent damage to her brother.

Tho it is open for debate whether the original beast was evenly matched/stronger than Mira's strongest TO, it is a fact that Elfman is lightyears away from mastering the "full form" and by the time he would be able to handle it, Mira will have TO'ed E.N.D