Not a bad description of Ike's ability. He gets quite serious when facing an enemy or when people mess with his friends (I think that's because they gave him that "I fight for my friends" line in SSBB) and, yeah, the guy is an accomplished swordsman (has to be to defeat the Black Knight).

For Ike's personality, I couldn't see much of it here, but I can tell you what it is like (I've watched walkthroughs of the two last Fire Emblem games. Always do that when I don't have the game and wish to know of the character's background, story, etc):

Ike is quite the kind type when it comes to interact with people who don't look suspicious. He shows he can be well humored, but can catch when to it in a violent way, like a certain bounty huntress). He also... isn't quite the brains in his group (Soren is), but he is definetly smart when it comes to guess what people's real intentions are (a skill that I think is necessary for people that lead the kind of life he does). The guy also doesn't care for things like, race, nationality or social status (things that in the medieval age he lives are enough to start wars. Literally), he learns that it doesn't matter along his journey.

You could say he is quite like Link, Marth and other swordsmen who are kind out of battle and beasts when they enter in it. And finally, he doesn't have a canon pair in his game, meaning you can write him with anyone, since you make it sound consistent.

Well, that's it for who Ike is. Until next time!

Kage: ...Um...wow. That was really interesting, as well scary. On a side note, BEAT THAT SUCKER UP IKE!