Except I did not come here to just make people mad or anything. I just am wondering why these type of characters seem so special to everyone else. Maybe I have weird tastes but that's me. I already said it's not to stop people from voting, I just don't get the appeal personally and wish someone could explain... And no, It's not because of the character being from an RPG...
I think we have plenty of counter-blocking swordsmen already at this point though. ((And personally... I prefer oddball characters... Kind of why I want Slime. He's an RPG character.))
Now you can continue. Please do not make this heated, I DON'T want any arguments.
If you are worried about him being a swordsman, don't. Yes, he can technically wield a sword. Or an axe or a mace.
However, there is a reason why most of the move sets we've built don't use the sword at all.
Isaac can manipulate the element of Earth through Psynergy. Think Psi powers like Ness or Lucas, but instead of Thunder or Fire, he causes earthquakes, summons falling rocks, or grows vines and nettles to hurt his opponents.
He also has Djinn to manipulate. Each Djinni has its own unique effect, from tying down enemies, to throwing giant boulders, to healing Isaac, or even more complex moves like draining hits. Once used, these spirits can summon more powerful forces like ancient creatures of mythology to deal even greater damage.
The Djinn can also change Isaac's elemental focus, allowing him to manipulate ice and water, or fire and lava, or wind and storms.
And let's talk about the weapons, for a moment. Even if we use Isaac's weapons, he need not ever swing a blade. This is because most of the weapons (and all of the most famous/powerful ones) in the series have alternate effects besides attacking. The most famous blade in the game, the Sol Blade, is most widely known for dropping a meteorite from the skies into Isaac's foes. The Tisiphone Edge summons Vengeance to riddle the foe with arrows. The Masamune attacks with two ethereal dragons.
And don't worry about Isaac counter-attacking either. While there is one single Djinni (of more than 70 in the game) that can counter, there is far too much potential to make that a part of his move set.
In short, Isaac would play drastically differently from any other character in
Smash. And even if he used his weapons, he would be anything but a retread swordsman. See the OP for more detail.