Nico's reaction to Leo's death was so fucking unreasonable?!?!?
He's so mad at him, to the point of not being able to think straight when finding out he's alive. To the point he needs so scream into the wild and physically harm him immediately upon his return.
And... for what? Because Leo didn't discuss it with him beforehand? Well, he couldn't have. He developed the plan when Nico was on his quest to deliver the statue. Because Nico had to feel Leo die? Well, newsflash, Leo had to actually die and feel every bit of that!
It's all about him. All about how upset Nico was that Leo committed suicide so the world wouldn't be destroyed. He shows' no sympathy whatsoever.