Jayce (Arcane): Jayce is an ambitious young man who wanted to use his Hextech technology to help Piltover, but love entanglements with Mel and Ambessa's violent advice, the desire for success and the search for magic drove him to make bad decisions that, while they took him to the top by entering the Council, then led him to lose himself and having to literally climb out of the hell of the future, destroy his creation, prevent the end of the world, rescue his friend and disentangle himself from Mel's schemes. 
 
Hector (Castlevania): a man mistreated by the world who chose to become a hermit, believing Dracula's lie that the world would be culled instead of exterminated. Later, upon discovering the truth, he allied himself with Carmilla after she manipulated him (though technically she was telling the truth) and ended up enslaved by her. He then makes matters worse by falling for Lenore's seductions, but after that, he pulls himself together and begins manipulating her back while plotting his escape and clearing the way for Isaac to kill Carmilla, thus atone for his betrayal.
 
Jayce and Hector have a lot in common, from starting out as naive characters, being seduced by a woman who led them to their downfall, and being intensely hated by their fandom due to their mistakes, in contrast to the more badass protagonists who always get it right (Viktor and Isaac). However, I like these kinds of characters more because I enjoy seeing them make mistakes and manage to overcome them even when the plot (and the audience) are against them. Unlike their counterparts, Jayce and Hector's development is more turbulent and less linear; you never know how they'll end up. 

I know that Jayce is generally hated because he's considered a spoiled, naive brat who sold himself for fame and glory; and Hector because he's, again, naive, betrayed Dracula (although I think it was kinda justified), and generally isn't as cool as his game counterpart. However, I think this is a result of having very sheltered lives (for different reasons) and suddenly being confronted with the real world, so this type of development is very consistent. 

Do you know any other character who hit rock bottom and then redeemed themselves? 

[Loved trope] Character fucked up horribly and has to climb out of their misery to fix what they did