(Svit, Slovakia, EU)
I want my main character to be an antihero. It is more difficult than I presumed. He will be a powerful king, but he will not hesitate to kill, rage wars and so on… He will actually like war and power. He will be a recognized tyrant.
The story starts when he abandons the throne and lets the kingdom fall. He sets on a journey, where he meets a woman… I want the woman to bring him back to his old position of the tyrant king, because the only one who is capable of holding the kingdom together is he and it has to be done by measures which cannot always be justified. He won’t always fight because he wants to save his kingdom but will have his selfish motives, but in the end he will be the one who takes on the responsibility of a king - a forever lonely man.
1. I do not know how much I can make him bad, selfish and cruel so that he won’t be hated by the readers. The reader should pity him a lot and forgive him his selfishness because he has to take on the status of the forever hated and forever lonely man.
2. The lover of the antihero. First I planned to make her a really lovable fragile girl, but recently I through whether she shouldn’t be less lady like and betray him at least once.
I can't tell you how to write your story, but I can share some thoughts.
First, I feel obliged to point out a couple of contradictions in your plot summary that you might want to think about.
First, if the hero is the tyrant you describe, why does he give up his kingdom? The fact that he gives it up suggests that something has changed in him, that he perhaps has come to decide his life no longer satisfies him in some way and he wants to search for something new - whether or not he knows what it is.
This suggests that when he returns to the throne
he will not be the same man he was before the journey began - he will be older and wiser. Some fundamental change will have taken place. Perhaps his motive for holding the kingdom together will be different?
This relates to your first question: how bad, selfish and cruel can the hero be. Generally, the key is that the villain must be even worse. The hero must have some quality that makes him a better ruler. Perhaps he rewards those who are loyal to him. Perhaps he keeps his word. Perhaps he ensures law and order. Something must make him the better choice, otherwise who would support his return? (In fact, people may only support his return if he can prove he has changed for the better.)
Second, it seems clear that the lover will be the impact character - someone who illustrates or argues for a way of being/acting that is different than the hero's. He has to decide by the climax whether to learn from her, be more like her, or to remain true to his former self.
If he is to end up lonely and hated, that suggests that he will ultimately reject her and remain the same. In that case, the reason he abandoned the kingdom, whatever he was seeking will turn out to be a fruitless endeavour. It suggests a tragic ending. The kingdom will be no better off.
On the other hand, if he learns something of value, becomes a better ruler, finds more meaning in his life, perhaps even finds love in the end, that would give you a happy ending. I suspect it would also be a more satisfying ending for the reader.
Finally, if you want the woman to betray the hero, the question is why? Does she do so for the greater good - and so teach him the value of selflessness? Or does this event show him why he should not be treacherous like her?
Alternatively, you could give him relationships with two women with different personalities, so that by realizing who he loves more he realizes how he must change.
Best of luck.