I don't know either really because i... actually like the bad-end. Okay this likely will be long... lets see if i can give examples.
Quinn is my only really powerful character and is like this to get a deeper meaning into what i am aiming for with where she is supposed to go. Yes, she is an extremely powerful Demonhunter who WILL chop most demons in half and likely has an advantage over Demon-Characters and NPCs alike, can take awfully lot of blows without being stopped and has an ability which pushes her to an extreme level (even when it ends in a two-week shutdown when its over but i digress!). The point of this character is the development she undergoes to become more powerful for a good curse with the cost of losing everything she is. From her personality, her humanity till to her existence as a VERY devoted Hunter (She values being a fighter against "unholy, malevolent Beasts" higher then her own sake for example and isnt even sure if she doesnt even hold it higher then her own brother.) and while she will grow more and more powerfull it will end up bringing her to an edge where she either gets stopped by other people during an RP or become unplayable outside of arranged events because i *want* to see and play this (i admit) typicall downfall scenario, and if she *does* become unplayable this will lead in her being killed by others since i will not make a cheap-escape if it passes a certain level. The strength here is just means to an end because i enjoy seeing the development happening and how people react to the fact that she is entirely ignorant to what is happening to her since the source "of all evil" keeps it hidden from her even better then from anyone else. So you could say she slowly changes color and while its obvious to anyone else, she can't see it and is confused why everyone is aiming at her, even feeling offended for it even tho others are just worried.
I strongly do enjoy the starting-as-normal-situation over this too however. My beloved, dearest Kira is my oldest Lismore-Character by three years of playing her and started out as what you would expect from someone who was born into proverty but had thievery as an option to survive this in the medieval times wielding sword and dagger. I played her this way because i couldn't imagine myself playing something big, and bulky with a shield... and im not a wise sorceress anyway. |D I also liked the idea of having her be what would be described as a "supportive Character". She is not the glorious Assassin that grows up after his family is killed, protecting his weaker sibling while on his way to become a true Hero that takes revenge for his loss, which is what i think is a very common history and character... She is instead that weaker sibling! That looks up to her brother and notices his greed for revenge and refuses to follow him since she is not this way... And i liked that a lot even though i dont think anyone except me knows. |D
Kira was just a Girl that i shared a lot of my personality with and grew up in a poor situation that only knew how to keep an opponent busy with her swords till she could finally make a run for it and i liked that. From there on i had the same way you said you like to go. She developed from there. She became much faster, as good as one can become in roof-climbing and jumping from one to another, developed a quick fighting-style she is very good with by now... Not because i thought "She needs this trait" but because i thought this would be logical consequences due to what happend to her. She really grew up from a young, lost little thief that needs to steal for a living and needs help to survive into an experienced, young women who *can* watch out for herself, who got used to all of this and considers stealing that normal that she doesn't feel guilty, or bad and is actually a nice person overall. What i still do enjoy here is obviously the fact that her live left many marks on her. Some of them physiological and psychological at once (like having her large, iconic, cute fennec-ears cut off as punishment from a pirate she tried to steal something back from). The character went through so much during her playtime and had enough open ends in her past that there is *still* so much to play with her to recover from all that and just *now* after her death at the very end of "the big one"-Event and her return a big crack in her soul is closing.
All in all; She sure did get stronger and lost some of her flaws that made her character interesting at the start, but developed enough other details and weaknesses that keep her interesting and give her much more room to grow then just over abilities or towards greatness.
Currently im also doing the very thing again. I play a mute, slave-character. She is very very intelligent, can change her scalecolor due to being a chameleon, has experience as a maiden and has a beautiful hand for writing, arts, so on. Thats all she can. She is poor, she is risen as a slave for less glorious purposes after she got kidnapped, is very weak, has no abilities at all that allow her to fight and needed the slave-character Lou described to not be abused and mistreated by other slaves before they where sold in lismore, since she is that weak. She needs other people to survive and exist... She can't do it on her own... But she is owned by Sansha and Tari now, meeting Sver, Kattilina and others and they start to teach her, finding out what weapon she can use, what her talents are except that, so on... I don't even care anymore what weapon she will end up with, since i do not mind if she can fight or not! It depends on Tari and Sver, who are trying to train her! She was suggested to wield a Dagger since she is so small (i had a Staff in mind at first) so i go with a dagger. What i enjoy with her, except the fact that it is fun to see how some characters interact with her since she cant speak, is that she is basically a blank slate that is shaped by what happens around her and what people do to her. She has no direction on her own since she is - like Lou's Daniel - entirely dependent on being told what to do, but is young enough to still be pulled out of it, which is actually happening. And im curious to see what she will turn into.