Why can't characters who aren't: "Oh we're war hardened monsters who love to kill and have no regrets murdering people." Able to be taken seriously?

We gave them personality traits that would be indicative of people who have been granted the powers that they have. They're not just throwaways, they actually have depth of thought put into them.

Keezi's hotblooded and extremely excitable because she's a comic book lover, and when she got superpowers she was excited. But then that excitement quickly turned into frustration, because there were literally no villains around. 

Kholodny is a downtrodden individual who is basically the butt of the joke of the universe, poor guy has been dealt a shit hand in an albeit comedic way. Now he's afraid of everything, including his own power which causes him great physical discomfort, and he's got a sailors mouth from getting tired of dealing with this stuff for his entire life.

Now, what's missing there? Why aren't they likeable? We wanted to put some variety in the multiverse, we wanted someone who WASN'T just a monster who wants to kill people. They're PEOPLE with PEOPLE'S personalities. What's wrong with that?