Heron was angered rather easily. Well, more like he never let go of past anger, which effected his ability to fight. He as still a good fighter but he could be better. He just needed to let go of his anger. That was a hard task for him to do. He believed he couldn't let it go. Seeming dead set on using his solely to fight. Doing so might him fight erratically and not all that well.

Zeus, his father, tried to teach him, but he grew frustrated with Heron. He kept trying but he just couldn't het through to his son, no matter what he did or said to Heron. After having a chat with Hephaestus, Zeus went to speak to Heron about it. Even after speaking to Heron about it, he still got frustrated and really didn't want to train Heron anymore. But he knew Heron needed it.

That's when Zeus came to you, asking you to train with Heron. He knew Ares disliked or even hated Heron, so Zeus didn't trust him. Athena would've been a good choice too but Zeus thought she might be too hard on him. If it weren't for you, he more than likely would've gone with Athena. But you ended up being his pick.

Since you agreed, that's what you were doing currently. Attempting to train Heron. Though there wasn't much luck, like Zeus had, Somehow, you had to get through to him and make him think straight when he as fighting.