Ike has been in the series since Brawl, but I haven't been a fan for the most part. His game of origin is the Fire Emblem series, where he stars in Path of Radiance and Radiant Dawn. Which are two Fire Emblem games I have not played.
He is the most unique Fire Emblem warrior with a sword in Smash Bros. While he's 70% like Marth/Roy/Lucina/Chrom, his sword attacks are much different.
His up special is a flurry of sword moves, and while it can be awful to those who get caught by it, most players against me easily avoided the attack.
His final smash Great Aether is a colorful assault against an unlucky opponent. It's okay, but not my favorite in the game.
When Kirby takes his power, he gets the ability to use the sword to smash the ground in a powerful burst of blue fire. While pretty, it's hard to hit people with it as it's easily dodge-able.
And online, I had very little luck with Ike. So I wasn't a big fan of him. Though I have seen a good number of players who actually are pretty decent with him. But he's certainly not my style, so it's almost impossible for me to win a match.