Hey heres another easy riddle for ya

I take two forms, I change at will,
The idea of mischief gives me a thrill.
Wrongly accused of killing my friend,
It almost brought my life to an end.
I survived, I escaped, and I sought retribution
The filthy rat must meet execution.
More clues are needed to solve this riddle,
I’ll skip to the end and miss the story’s middle.
I escaped death twice; the end was near,
He did not know I would soon disappear.
He went to save me, save my life,
My death would soon become his strife.
It was not an act of evil or of hate,
My death had long since been veiled fate.


Who is it?
Danz_angel x