Some people (like me for example) have a lot of characters, whether they're otaku senshi or completely original characters from your own fiction. And sometimes it's nice to have a way to organize all the information you currently have for them in a single place for easy reference when writing.
And that's where Character Sheets come in. Some people make their own, but the internet has tons and tons of different templates to use, varying in depth and breadth of information to fill out. I personally found it kind of tedious to fill out the longer ones at times because of all the writing and typing I have to do to answer the questions, but I found these two references today that simplify it well.
This is a character checklist. Instead of forcing you to fill a thousand blanks in your own words, this just lets you do a multiple choice style sheet for your character. Far less writing is needed, and it also asks a decent amount of personality based questions that force you to think about you character a bit more deeply too. I think that this kind of sheet is also perfect for comparing characters with each other as an overview, to see where they do and don't match up.
And for people that want a more in depth version of the checklist, there's this resource:
https://drive.google.com/file/d/0B_Pus_x_263yOV9vM3J6djN0bFE/view
It's a character checklist booklet that you can even print out and have a physical version of if you like that kind of thing. There are more blanks, but they all only need one word answers, and the rest are just rankings and more multiple choices.
I'll be posting more interesting character sheets here if I find them!