An entry in Fortnightly Topic Challenge #35: Restricted Title 1.
I'm not really into Pokemon, you see
But a friend of mine is, as much as can be.
He goes on and on about this move and that,
And I can't be bothered to remember the smallest fact.
Recently, he described to me
A Pokemon quite intriguing.
He said it was brutal and ruthless,
And that it was constantly attacking.
Curious despite myself, I want to see it.
What does this Pokemon look like, exactly?
The only other detail I have, however
Is that it has decent power.
Oh, I almost forgot, he also told me
That it can be found, at least originally, only by evolving.
Can you help me figure out what Pokemon "my friend" was talking about? I need only the name, from there I can search to figure out what it looks like myself!