'''Basic Trope''': A character bounces between hero and villain.
* '''Straight''': Eva joins AliceAndBob's fight against TheEmpire, but betrays them later on... only to flip back again later. And ''again'' when they meet TheDragon. And after the dragon pulls YouHaveOutlivedYourUsefulness...
* '''Exaggerated''': Eva changes sides OnceAnEpisode as a RunningGag.
* '''Downplayed''': Eva is a TrueNeutral who assists whichever side currently suits her goals better.
* '''Justified''':
** Eva has a SplitPersonality; one with TheEmpire, the other with them, thus causing her switch over.
** Alternately: Eva is really indecisive.
** Alternately: Eva is ChaoticNeutral.
** Alternately: Eva is a mercenary.
** Alternately Alternately: This conflict is not a simple "vs. TheEmpire" fight, despite the fact that TheEmpire is fighting, but is very morally gray. The truth is, Eva is the most black and white character there, but the shifting ideals, policies, and harm each is doing causes the person who benefits from Eva's help, and who's help benefits Eva, to constantly change, but Eva herself never really changes "sides". This makes it seem as if she is constantly betraying both sides.
* '''Inverted''': Eva is a loyal agent, but her agency keeps going over to the side of good... then evil... then good again.
* '''Subverted''':
** After joining the heroes, Eva ''appears'' to betray them... but is actually just pretending to rejoin TheEmpire so she can snag the MacGuffin.
** Eva sometimes fights alongside the heroes and sometimes against them, but eventually reveals that when she fights against them, it's only to [[TricksterMentor make them stronger]].
* '''Double Subverted''':
** Actually, she did join the empire, but did so carefully so that she could claim to be only after the MacGuffin if it looked like the heroes would win, which they did.
** Eva's story doesn't actually check out. Many of the fights had far too much at stake, and no useful lesson. The whole TricksterMentor thing is just [[MultilayerFacade another mask]].
* '''Parodied''': Eva just so happens to switch sides right before she gets her reward for following that side, and keeps making the same mistake every time she switches.
* '''Zig Zagged''':
** Almost always is, between "HeelFaceTurn" and "FaceHeelTurn".
** Alternately: Some seasons Eva keeps switching sides, others she stays on the same side the whole time.
* '''Averted''':
** Eva never betrays them.
** Eve is completely up front about having her own agenda, although not necessarily about what that agenda is. She's never ''on'' a side to begin with.
** Eva switches sides and remains on that side for the rest of the series.
* '''Enforced''': "Eva isn't working out as a hero; let's have her go back to TheEmpire!" "...Wait, no, that isn't working..."
* '''Lampshaded''':
** "Pick a side, Eva! I've had enough of this! If you want to stay with us, then come back inside and I will pretend this never happened, but if not...get lost. Go away and never come back!"
** The secret base has a literal revolving door, marked "Eva."
** When asked what side she's on, Eva has to check her watch.
* '''Invoked''': Eva is a double agent, and this is the most convincing way to get information on both sides.
* '''Exploited''': ???
* '''Defied''':
** Eva performs a HeelFaceTurn or a FaceHeelTurn. And that's it.
** When Eva tries to switch sides, she is RewardedAsATraitorDeserves.
* '''Discussed''': "I still can't trust Eva. I just can't, there's no reason to. She doesn't even seem as though she's changed at all since she stabbed us in the back already, what's to say she won't do it again when things get tough?"
* '''Conversed''': "I've lost track: which side is Eva on this episode?"
* '''Deconstructed''': TheEmpire has been helping Eva achieve her dreams, but she starts questioning their methods after meeting Alice and Bob and ends up joining their fight. However, her past makes it difficult for her to fit in with [[TrueCompanions the other heroes]], and she goes back to TheEmpire... but can't stand working for them knowing all they've done, so she rejoins the heroes. But now they trust her even ''less'', and she doesn't have anywhere she fits in anymore.
* '''Reconstructed''':
** Or so she thinks. While Alice and Bob are still unwilling to trust her, WideEyedIdealist Colin has been going to bat for Eva every time the discussion turns in that direction and has been very convincing in his defense, finally making Alice and Bob agree to give her at least one more chance. Accepted into the group once more, Eva finds a place she can do good and comes to settle in.
** Rejected by both sides Eva becomes a WildCard striving toward her own goals while [[ChaoticNeutral manipulating both sides]]. Because she disagrees with TheEmpire's more [[EvenEvilHasStandards evil actions]] she will [[EnemyMine help out the heroes]] when the empire is doing something really bad, but she doesn't consider herself their friend and will leave once they have won the fight.
* '''Played For Laughs''': Eva switches sides so often that it stops being treated seriously and just becomes ridiculous.
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%% Optional items, added after Conversed, at your discretion:
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%%* '''Implied''': ???
%%* '''Plotted A Good Waste''': ???
%%* '''Played For Drama''': ???