@LibratheScales Are you aware that I am one of those who has already denied that ability before? However, in this particular setting it'll work fine because the magic is much more magical than scientific. I would like to introduce 2 limits to it though. Firstly, she cannot change Celesticite into something else, nor can she construct Celesticite from other things. If she tries, she will get a brief headache and make absolutely no progress. (See clarification in second paragraph.) Secondly, she cannot create something unless she's able to visual the entire inner workings of it. For example, she could create a brick because they're simple, but if she wanted to build a mechanical firearm, she'd need to know the exact layout of the interior parts like the pin and the trigger and the ejection mechanism. Having blueprints of the object is fine.
Clarification on the first limit: I don't know how you want the ability to work if she fails to construct something halfway through, but with Celesticite the moment she tries to build or destroy it, she gets a brief headache and the process stops, like what might happen if you double clicked a shortcut on your desktop and it said "No file found at target location". It doesn't even open the program before crashing. I'm sorry but I can't explain why without telling a major spoiler so if you can accept this limit, don't question it :D
@~\The Talentless/~ A few issues with your character. I'll go through them in order of importance.
First off: I said in the rules that any abilities after the second will be almost negligible in power, and by this we're talking stuff like being able to see 50% better in the dark, or always knowing if your favourite TV show is going to be cancelled that week. Definitely not something like Colossal, which imo is stronger than his first listed ability.
Secondly, you underestimate the physical strength of celestials. My character can have flesh tougher than diamond that completely nullifies damage, but an average punch from a demon would still send her flying a couple of meters backwards. You might want to add the ability to anchor himself to the ground.
Thirdly, each player starts with only one piece of Celesticite since as I explained at some point somewhere, your abilities are stronger the more of it you have. Or are these two pieces smaller in mass than an average piece? If so, that's fine.
Fourthly, you said his muscles will begin to tear apart if he over-exerts himself. That's fine, but I'll be keeping a close eye on how much this is happening.
As another note since I don't think Fifthly is a real world (though autocorrect suggests it is), I'll also be watching the use of Eyes on the Prize. From a psychological point of view, someone who can't feel pain won't bother blocking or dodging, they'll just take the damage head-on, especially if they're naturally cocky like he is.
I get the impression that he and Shirona are going to... well I want to say get on like a house on fire, but they could end up despising one another too. They'll certainly have a rivalry to have the most kills that's for sure.