Ooh gorgeous!

Oh the feels. The impending Feels. I can feels them. And they are like a great wall of Feels.

so.. RIP RANI?

The death flashbacks hurt. T_T

The flashback method is good, but to deliver the most devastating pain to your readers it's better to use it before said character enters the death scene, actually, the sooner the better, for it's a great way to reinforce the bond between character and reader. For example, you could have placed the flashbacks while she was teaching her students in a way to show that even a great master had vulnerabilities and troubles in the past.

Then you kill her, it will hurt way, way more.

flashback like this is an obvious way to tell that character dead is imminent(there' some subverted case but it's very rare)
if put in earlier, reader can guess immediately that the character will die(like soldier mentioned or showing picture of his family cliche)
I agree that showing bond between character is better way for emotional impact
but that require lots of character development, which sadly I didn't have much time to do for her.
I really wish I can give her more character development but time is not on my side(I can only manage 4-5 page a month)
it's a really cheap and cliche way for "emotional depart" and I'm not proud of using it

Oh, I agree and understand completely! I suffer from similar problems although from a different medium (I just write stories, I did scripts for comics years ago) if you want I can tell you about some tricks and tips.
Nevertheless, keep up the good work!
And it's a pain to write from the phone, forgive any misspellings or mistakes!

I have a strong feeling she will remember something useful at the last minute. All signs lead to it after the mention of the overhulk form. Why else would you mention something like that?