Characters who sometimes act as villains and sometimes they don't. Typically, this means that they "switch sides" (i.e. go back and forth) more than twice. The villain is only redeemed if he or she stops switching sides and decides to stay good in the end.
IMPORTANT: Do not add Complete Monsters to this category. It's impossible for an On & Off Villain to be a Complete Monster as they remain eternally and irreversibly evil at all times. Although some of these villains may never fully redeem themselves; they are not complete monsters.