This has my attention. If I might ask, which of these four characters seem most plausible for Brilliance, and so which one should I pursue?

#1 - Animated suit of armor, origin unknown at the moment, dialogue consisting mostly of grunts (though he can speak and will), wields a hefty, intimidating claymore, surrounded in cold air and possesses limited mastery over shadow. Is hella tall when standing up, and he is (most likely) human. Or, was... 
#2 - Old researcher, hails from Sord (may be government or private sector), prioritizes his own set of agendas over himself and others (to an extent; he's still a moral man, but...), still dresses in his old, formal attire for a number of reasons; one being that people can find him easier. Human magic-user and face-puncher.
#3 - This guy is an oddball. His appearance and choice of weapon will scream "Villain!" due to an incident in the past, but he's actually a really sweet and doggedly nice human guy outside of battle, and he's not much different in battle either, only switching to a victory-based mindset with a tendency to jump in the line of fire for others.
#4 - Human knight of Zenterr, granted autonomy by an unknown-as-of-yet direct superior; he's investigating something at the time the story begins. Slightly sociopathic personality, but is focused on upholding his given duty. Wields a pole-arm, and showcases extreme disciplined skill in combat, to make up for his clashing elements.

I'll await your response. I've always secretly wanted to see how a "Tales of" story would grow...