Vexing Shusher can't be countered.
: Target spell can't be countered by spells or abilities.
5/1/2008 After Vexing Shusher's ability resolves, any spells or abilities that would counter the targeted spell will still resolve. They just won't counter that spell.
5/1/2008 Vexing Shusher's ability won't prevent the targeted spell from being countered by the game rules (for example, if all its targets are illegal).