In my opinion, Frank is the absolute sweetest out of the 7. He just cares so much about everyone, even Leo at first when he’s pretty sure Leo is “moving in on his girl,” and he’s an amazing friend. Frank is insecure about himself even though he’s quite strong and built, but he never puts others down. He’s more powerful than most demigods but he doesn’t let it get to his head, in fact he’s also insecure about that. Also I think it’s really sweet that he was praying and hoping that Apollo was his father before he found out it was Mars. He was able to help Hazel accept her fate and her curse, so now she’s able to control it and more confident in herself. In conclusion, without Frank, the world would’ve ended multiple times and I think he’s highly under-appreciated.