Just like gravity, I see x3
Well, Oliver is a Charmeleon with a grumpy attitude and a serious minded disposition. More truthfully though, he's absent minded and rather calm, even while intelligent. He wants to be taken seriously and seen as a hero, which he will make a wish to Jirachi to become, and thus displacing Verdanté as the Hero of Truth. (Also called the Sage of Truth.)
He does adore stories and their heroes, and he genuinely wants to live as one, but overbearing pressure from his mom (A former hero herself, who traveled with Saber) and the villagers he lives with has cracked him and ruptured his self-esteem. His mom is excessively tough in raising him, and he's expected to be heroic, so he has no positive reinforcement, you see.
The second is Nena, a Dewott. Despite her enigmatic and lively personality, she's actually rather calm and intelligent. She acts dull-witted and goofy so that others will like her, and she's grown into the mask. Her own insecurities have driven her to heroism, and she's often the first to take action and do what's right. She's the rightful Hero of Ideals, but she's just not ready yet. Oliver's wish will spin things out of control and rush her into her role as the Knight of Ideals, even while she's not ready.
(She doesn't know she's supposed to be the hero yet.)
And lastly is Saber (His real name is Marcel), a Keldeo, and a hero as previously mentioned. Without any heroic things to do, he's become despondant, immature, and selfish. He's cut off contact with his former friends, and wanders around the continent aimlessly. He's also sick of being unnappreciated for his former heroics, despite the fact that they happened several decades ago. His personal story will be focused on redemption.
Any questions? Feel free to ask, for I seek a large tip. :3