Has the "beast" devoured the article?
When you returned to a game you haven't played in years and discover you're still [a] beast at it.
"Beast" is slang. Urban dictionary says:
a person that is extremely talented at whatever they do and always display great determination, dedication, and resilience to always win or want to win.
Btw, note that your sentence isn't a complete sentence.
Oh god, look now "beast" has got a verb from too: beasted.
- To have excelled at something as if using super-human beast like skills.
I totally beasted my math test, got an A.
- Beasted is a word [some people] use in call of duty [read video games] when they absolutely destroy you.
Player1: kills you "OHH! BEASTED!!"
And as ColleenV mentioned in the comments, there is beast mode.
a state of performing something, especially difficult activities, with extreme power, skill, or determination.
Merriam Webster defines it as:
An aggressive persona one might assume when in competition
You turn it on when you are breathing heavy, on your last set, squatting 405 lbs.