The challenge

"If by my life or death I can protect you, I will."
- Challenge prompt

When I saw this prompt I imediatly thought about her and this unfinished shrine. I think Sailor Moon is the personification of this promt as she tries to protect everyone and everything in all the media; but I will be talking just about manga here.

Durning whole series she tries to protect everyone and she comes to touch death a few times in the series.

1. Dark Kingdom Arc

As Sailor Moon she went against Metalia after she thought she failed protecting her dearest friends and she used all her energy risking her own life to banish the enemy.

2. Infinity Arc

In the last battle against Pharaoh 90 she gathers all her power and uses the callice to try and destroy him, which for a moment leads everyone thinking she died, because this triggers the talismas to recall Sailor Saturn, the Sailor warrior of Destruction.

“I will release the power of both the legendary Moon Chalice and the Silver Imperium Crystal inside of him!”
- Infinity Arc

3. Stars Arc - Galaxia

“I reached out because I felt the lonliness inside you.”
- Stars Arc, Act 60

Another show of her desire to protect everybody is when she tries to save and protect Galaxia, the one that took everybody from her, she still protected her even if Chaos took her away.

4. Stars Arc - Courdon

And the last show is when she jumps in the courdon risking her core and escence to save everybody or destroy the place where all stars are born.

“Chibi Chibi; I won't give up. Everybody believed in me... At the end of a battle there is hope for the future. I will make a future for my friends. So, don't you ever give up ether.”
- Stars Arc, Act 60

After her jump in the Courdon, Sailor Cosmos actually comes to another conclusion which is the final confirmation as to why this challenge was a perfect for her.

“I've received great powers from Eternal Sailor Moon. The power to lose everything...and the power to save everything.”
- Stars Arc, Act 60

I think that more than this can not prove she is the perfect heroine for this challenge.