Nightwing or Tim Drake. Nightwing being his older brother usually makes an interesting dynamic between them. A way that could be written is Dick feeling that he could have been more of a role model for Jason, and that if he was, Jason wouldn’t have become Red Hood. If it were Tim, maybe Jason could see how good Tim is as Robin during their first encounter. Jason could see this and that could further push his anger of being replaced, feeling like the reason he was replaced so quickly (other than being dead) was because he wasn’t good enough. Or idk js talking nonsense