Hey-- don't say that! [only Maya is allowed to call herself useless, thanks] You just said you could cast all those spells! And you can write! And be sarcastic! [is this a skill] You're not useless!

[Also the answer to why she cares is pretty simple, and he said it himself: she's the stupidly optimistic type]

[or maybe just the stupid type]

I'm not gonna let you disintegrate! What is it, magic spells? Magic rocks? Magic potions?!