Slash! Bang! Crash!

I have a magic wand.
That takes me to my dojo.
There I can do anything,
Even fight off some ninja!
And unleash my true rage.
I am immortal too,
So you can't kill me!
I am like dragon,
You're like a fly,
I will win all the time!
Except...
If you're me.
But that won't happen because,
I'm me not you!
Mwahahah!
But I will give you a lending hand.
I will welcome you into my dojo,
And we will fight ninja together.
But all this from a measly pen,
Then bang! You're here
Then bang! You're there