A lot of people want this sword, so I've been coming up with a few ideas and this is what I eventually ended up with.
Here's an idea for a line of them.

Mysterious Sword (2*)
A confusing blade of unknown origin. It's said to be the missing link between light and dark.

Type

Normal

Appearance

Like a sealed sword, only without all the glowy stuff, and it's black fading to white from hilt to tip.

Regular Attack

Like a heavy sword's swipe.

Charge Attack

Again, like a heavy sword.

Dimensionally Imperfect Blade (3*)

A fine-tuned sword, yet rough around the edges.

Type

Elemental/Shadow

Appearance

Like a sealed sword, only without all the glowy stuff, and the tip is enlarged, completely black except for the hilt which is white, and the tip, which is glowing yellow.

Regular Attack

Like a heavy sword's swipe, but with two trails, one being purple the other yellow.

Charge Attack

More or less like Troika, only instead of the smash when you move forward, it's a 360 degree knockback.

Perfectly-Balanced Swordspiece (4*)

This blade's edge, is the edge of light and darkness itself.

Type

Elemental/Shadow

Appearance

Like a sealed sword, only without all the glowy stuff, and the tip is enlarged more, bringing more of the rest of the sword with it, and it's completely black except for the hilt which is white, and the tip, which is glowing yellow and has glowing purple spikes. More fancier than the 3* (think of something).

Regular Attack

Like a heavy sword's swipe, but with two trails, one being purple the other yellow.

Charge Attack

More or less like Troika, only instead of the smash when you move forward, it's a 360 degree knockback with spikes flying in the direction you aimed the attack.

Edge of Life and Death (5*)

This sword is the holy AND unholy symbol of light and darkness. It holds them together in perfect harmony.

Type

Elemental/Shadow

Appearance

Like the 4* version, but now The whole sword is glowing, switching between purple and yellow, and there's a blue line smack-bang in the middle of the sword on both sides. It also has a sparkle on the main sword body.

Regular Attack

Like a heavy sword's swipe, but with two trails, one being purple the other yellow. More fancier than the 4* (again, think of something).

Charge Attack

More or less like Troika, only instead of the smash when you move forward, it's a 360 degree knockback with larger spikes flying in the direction you aimed the attack. (also think of something to make the charge better than the 4*)