While I have said, in the past, to use D&D as a reference-point for looking up appropriate spells for each tier of magic, please keep in mind that the world is still more based on, and akin too, an MMORPG, rather than a turn-based tabletop game.  The only correlation between FOTO and D&D is that the spell-tiers of each magic-castig class is a good guideline for what level of powers a spell of X tier shoudl/could have. 

The main issue isn't the [i]way[/i] the additional chaos effects afflicts people, it's that some of them outright bypasses any need for consent or approval from a different player. Take the affliction that causes everyone in a set raidus around the caster to speak complete jibberish for example, if this effect occurs, every player within said distance would be [i]forced[/i], whetever they wanted to or not, to be unable to converse or interact verbally. Even if the other players didn't wish for this, they'd have no say in the matter, which is the main issue. Yes, you [i]could[/i] remove some of the things that afflict other people besides the caster and target, but then you're also taking away a large part of the whole point with the character as well.

A beter idea would perhaps just be to ask everyone else in the RP if they're cool with roleplaying out the effects of Mercurio's spells, regardless of what or who they hit, when they do hit. But then, you'd need consent from [i][b]everyone[/b][/i], not just the majority.

The issue witht he karma points is still that he can rack up a very large sum of points in very little time, even if e can only earn one within a set period of time. Given his character and backstoy, he also seems prone to misfortune, which will readily supply him with a constant influx of these points. Additionally, I have no way of keeping track of how many points he has PRIOR to joining the story, nor will I be able to constantly check in your CS just to check if there has been any edits to the number of points he's banked. Now if there was a hard-acp on how many points he could store, say 10 or so, that'd be more agreeable, but again, doing that will ultimately diminish the character's original concept.

I'm not opposed to the idea at all. It's unique enough (to me at least) that I can say I haven't seen a character quite like this before. However, I'm not certain the concept lends itself overly well to a more free-form RP, as opposed to a pen & paper tabletop with actual dice and note-keeping.

Also, while his reason for wanting to join the group may be to ivestigate Serafaye, there are some flaws with that concept.

1. He isn't present in the story, and Serafaye has already been released from her crystal prison. As such, there would be no way for him to reasonably figure out that she's an otherworlder.
2. While [i]he[/i] may be interested in following her around, I'm not so sure she'd be overly happy to have an obsessive stalker constantly barraging her with questions.
3. Even if he may be pragmatic, his character is still described as rather unstable and outwardly unsettling, sort of like Cicero from Skyrim... Except less jester and more former-slave-now-turned-fortune teller... xD

But, hey, if everyone else in the roleplay is fine with, I suppose there's not really any issue. So, go ahead and let me know what you think, boys and girls. And remember. I don't care either way - is not an answer. I don't want a lazy shoulder-shrug, I want you to read the sheet and the character and let both me ad Wretch know if you're fine with his powers and abilities.