Ytdyklly

My character, Day, is the son of a dictator and the director of state-sanctioned and sponsored torture of mutated humans, one of whom is my MC. He killed his own sister to prove to his father that he was worthy of his government position.

After being held hostage by the mutants after they escape custody, he tries to kill the youngest of the group, a six year old. He truly believes that his father's fascist rule and the outlawing of freedoms of speech, press, religion, etc. are completely justified and called for.

TL;DR: he's extremely misguided, kills indiscriminately, and shows no remorse.

I do plan to have Day switch sides eventually, in a kind of a Darth Vader, the-light-was-inside-you-all-along way. But with all of his horrible behavior and actions, how can I redeem him, and how do I not rush redemption?

Is it plausible for a villain of his caliber to be redeemed, or will readers find it forced? Is it cliche to even want a redemption arc (through friendship/love) for such a bad guy?

Monica's excellent answer provides you with the how, but I'd like to touch on when, since you asked "how soon is too soon?"

The rough answer is "It's too soon if the villain hasn't earned it."

Your villain has to walk all the way back through the brainwashing/teaching/propaganda etc. which got the person to the dark place s/he began the story. The villain has to unwind all the lies, and the longer s/he swallowed and believed lies, the longer (or the more violently dramatic) the unwinding and walkback have to be.

Additionally, there are two important facets to redemption you can't skip: 1) acknowledging that s/he was wrong, and 2) making amends for the villainy s/he did, to the extent that it's possible.

If the villain just sees the Mutant do something selfless, s/he is not just going to go "Oh, gosh, I see now that Daddy God-King has been wrong all these years. Let me dash off to help the mutuants overthrow him!" and expect that to be sufficient.

The villain has to un-think or re-learn all the negative things s/he was taught, which takes time and effort (as Monica eloquently showed). Then the villain has to realize "I did evil things. Those things were wrong." That sense of "I was wrong" has to stick. No villain can be redeemed without acknowledging this. Rationalizing or villainsplaining won't cut it.

Finally the villain has to do something to try to rebalance the scales. Whether that's working to overthrow Evil Daddy God-King, helping mutants escape, lobbying legislators to change laws, or a suicide bombing, if the villain does not do some good to balance out the bad, the villain isn't redeemed. It may be that the villain murdered children. That's something you can't ever really make amends for, but you can carry the weight of it on your soul, and try to save as many future children as you can, or give your life to protect one.

The villain has to try to be as good as s/he was bad to earn redemption, or your readers may feel cheated.

The light is inside him; it just needs a path out. Not a big gaping doorway that opens all at once, but small tendrils. Think "many drips carve a rock", not sudden change.

How do you do that? In a lot of fiction that I've read (and I suspect there's psychology behind this, but I don't know), the first cracks come with perceived inconsistency and self-doubt. Your character has been raised with a certain worldview, has had certain ideas baked in from birth -- and that's all fine so long as he lives in a nice, tidy world. But put him in some situations where the reality in front of him seems to conflict with those ideas, and you have the beginnings of self-doubt and eventual redemption.

He probably doesn't just believe that mutants are bad, for example. He's heard his dictator father go on at length about specific ways that mutants are bad, same as we hear bigots in our world give "reasons" that their targets are bad. Suppose, for example, that dictator-dad has taught Day that mutants are bad because they're incapable of behaving morally -- their brains are wired differently or some such. So long as Day believes that mutants are really just kudzu with weapons, a nuisance to be removed with extreme prejudice, all is fine in Day's mind. But what happens when Day sees a mutant do something against the mutant's self-interest, like putting himself in danger to save a human from harm? Whoa, that doesn't sound like amoral kudzu now, does it?

Now, one mutant is a fluke; Day's programming won't be cracked that easily. (Dad is a successful dictator, after all.) But it's a crack. Let some time pass and then open another crack -- maybe Dad said that these vermin live like animals and don't care for their young or whatever, and then Day gets a glimpse of a functional mutant family.

Cracks grow and spread over time. One he can shrug off (but have him notice it or it's not really a crack). Two he might comment on (internal dialogue; he's not ready to confront Dad). Three he might start to question some less-important "facts" he knows. Over time, it adds up.

Think about any attitude you have held strongly but changed. Maybe it was a political ideal or a religious belief or a deeply personal matter of identity. How did you come to transform from one position to another? Most likely it was gradually, over time, bit by bit as you tried to fit new facts or encounters into your original frame and found that things didn't fit so well. While (I hope) you aren't starting from murderous demagoguery like your character, the process is still similar. It's just the magnitude that's different. And besides, you're trying to connect with your readers, who also have gone through changes (haven't we all?) but who mostly didn't start from murderous demagoguery. To connect with your readers you want to resonate with their experiences. Strict accuracy in turning a mutant-hating dictator's kid to the light side isn't as important as evoking your readers' feelings of recognition of change in progress.

He should be a fully fleshed, three dimensional character with more going on in his mind than daddy told him mutants are bad. Your mutants taking him hostage will initially reinforce such thoughts. The ‘good guys’ - if they exist - don’t usually kidnap people.

As Monica said, it is a gradual process and there will be setbacks.

One man’s freedom fighter is another man’s terrorist. It is a matter of perspective and degree.

I am playing with a scenario where an assassin is being persuaded to assist in at least investigating who might be ultimately responsible for the assassination he just committed. It is a very gradual process, one character refers to it as seduction and much like training a colt. Gentleness, consistency and logic slowly allow him to entertain the possibility of helping these people - in as much as honour and duty allow.

You want your character to suddenly realize he was wrong after more evidence has been presented that Dad was right. You need someone with outstanding people skills and a ton of patience.

Force will never work. One thing that you will probably need to show is that there is evil in everyone. Your most virtuous character has done something worth regretting. Shades of grey, not black and white. Black and white - aside from being a little naive - tends to be dull.

Day must make a choice for reasons of his own that are both unique to him and firmly rooted in his soul.

Consider Javert - his life spent chasing criminals and certain of the immutability of human nature. He encounters Jean Valjean several times, but seeing Valjean risk his own life to save another’s drove home how wrong he’d been, the damage he had wrought and that man can be redeemed. Valjean was redeemed when a saintly bishop bought his soul for god. The generosity of the act sent him in a tailspin, from which he emerged an altered man.

Valjean dedicates his life to helping others and raising the daughter of a woman his company wronged. Javert writes a damning letter to officials and leaps into the Seine.

How will your character cope with an awareness of all that he has done having been wrong? He probably uses the rationale that such deeds were necessary for the safety of the State.

Terrible deeds are done in the name of national security. My MC kills many people, believing it to be right and justified - until he receives orders he cannot reconcile with his moral code.

Have Day realize on his own that he had been duped. He might start by thinking ‘Not all mutants are evil. Maybe I should listen to these people - if they ever take the gag out - might ask a question too’.

Much of this will be determined by his age and level of maturity. If he is some callow kid following daddy’s orders because daddy said so, it can be sudden, but I probably would have put the book down not really caring if villain jr learns something.

Good villains are not easy to write. Even the darkest does not consider himself a villain - perhaps a tool of destiny - but never a villain. You have to learn everything there is to know about both Day and his father - not just the labels you assigned them. When writing them, be on their side. Love them and know the better your villain, the better your story. Do not make them cardboard cutouts.

Make him real, like him and get inside his head. Once there, ask him what it would take to turn him.