Alright, it took me a bit longer to get to this one (mostly cause I was scared after Raven) but you did promise me a new character, and I have a severe case of writer's block in Heir, so here I go....
Your question first: My first thought is a resounding YES, but I guess it depends on what your goal is in boosting up his intelligence and toning done his anger. If you are trying to make him more likable, you would have a long way to go and I wouldn't think just those boosts would fix it, but if you just what to tone it down a bit so we don't run away screaming so fast, than good. I can handle an angry person, just as long as I don't have to go so far into his head as you had it last time, get a break from him every once in awhile and don't have to see all the fruits of his labors (ie all sorts of poor people dying every two seconds). But if you don't tone down the anger, I wouldn't want him any smarter than he is already because then he would be smart, nasty, and magical and I would never feel safe in a dark alley again!
Thoughts while reading:
'gasps of air were heard' by who and who's making them? Sentence seems a little awkward....
Ah, so it is this Isaac fellow who is gasping. Must be a way to simplify this concept.
And were back to the swearing... This doesn't bode well...
You have a tendency to use a lot of phrases like 'suddenly,' 'before he knew what was happening,' 'now,' 'instantly responded,' and it is all fluffy. If it's his initial response, just have him do it first.
Is your paragraph on essences supposed to do anything but confuse me at this point? I assume it's details on your magic system, but it is all going over my head... but that's what I get for being less intelligent than the average bear... maybe it will make more since later.
Your transitions/reactions seem a bit abrupt. Like you spend a lot of time telling me how surprised he is and describing the town (good descriptions by the way) setting me up for a leisurely pace, and now he is frantically banging at the door. When did that happen? And then again Marlon seems to have an complete change of heart about Isaac, but I guess it had to do with the magic (which was also cool)...
Tone down the accent a little bit. It's a bit jarring right now. I do like the dialogue overall though.
Wow, Isaac must be really light! Marlon is just flinging him around! But I thought Isaac was taller than him...
Overall Impression:
Alright, a lot different from last time. Before I felt I knew everything there was to know about your characters (and it wasn't pretty) and now I don't know much about this new guy except his post and use of magic. So I don't hate him, but I don't love him yet either... which I see as a big improvement, so thumbs up over here. Scene (interaction between Isaac and Marlon)was very good, once we got to it but you could very easily cut down all that time he stands in the snow thinking without missing much. That may be it from me... Good writing, good descriptions, and good work.
Now I have to go back to Heir again... sometimes I wish parts of my book would just write themselves.... *sigh*