Situation: Player A casts {Paralyzing Grasp} on Player B's {Guile}
Player B responds with {Dismiss}
Player A responds with {Redirect} having {Dismiss} target itself
{Guile}'s ability triggers exiling {Dismiss}
A couple questions:
1. Since {Dismiss} countered itself, does Player B draw a card?
2. Can Player B cast {Dismiss} from exile to target Player A's {Paralyzing Grasp} which is still unresolved on the stack?
You can't {redirect} to have {dismiss} target itself. You can have it targeting redirect though.
Effect will be that {dismiss} will be countered because of an illegal target, so not because of a spell or effect. Thus {guile} will not trigger. {dismiss} does not go to exile but to graveyard.
EDIT: for complete-ness sake, player B does not draw a card since {dismiss} was countered.