On devoice
From Scriptwiki
The on DEVOICE event triggers when a user on a channel is devoiced.
on <level>:DEVOICE:<#[,#]>:<commands>
$vnick refers to the user who was devoiced.
Example
Triggers when a user with level owner was devoiced in #help.script or #mIRC and voices him again:
on 999:DEVOICE:#help.script,#mIRC: { mode $chan +v $vnick }
See Also
On voice triggers when a user was voiced.