Twenty-year-old vindictive Johnny leaves the reform school, forms a one man army with nature's creatures, and avenges his parents' assassins, the last one being the head of state with impregnable security.

I noted your comments and will moderate the logline.Thanks.

I am from India.Anybody interested to join me in polishing and Americanizing the script as our English is a little different.Thanks

You don't need to include your protag's name. Unless the protag is a famous person, character names are meaningless and tend to clutter the logline.

Better to use a descriptive noun and a well-chosen adjective. This will make the character clearer and the logline more succinct:

"A rebellious juvenile delinquent forms a one man army with nature's creatures to avenge his parents death at the hands of corrupt assassins, one of whom is a head of state with impregnable security."