Do We Have This One?

He's older and ostensibly wiser, and more than willing to impart his wisdom upon his children, younger siblings, or other youngster.

There's just one problem: His advice sucks!

Sometimes he's just clueless, but other times, he's intentionally misleading his protege.

The most common subversion of The Obi Wan.

Examples:

Life With Derek: Derek Venturi is constantly misguiding his younger brother Edwin, encouraging Edwin to be a delinquent like him, giving him faulty social advice, and sometimes intentionally misleading Edwin for his own amusement.

Trojan War: Seth is training Josh in the ways of seducing women. Unfortunately, his advice consists mostly of idiotic pickup lines. After trying them for himself, Josh calls him out, quite aptly stating "You know nothing!"