1) Scissor Blade from Kill La Kill. Guessed by /u/Hyteg Sword like. Part is used by main protagonist and part is used by a bad guy.

2) Lambent Light (Asuna's Rapier) from Sword Art Online. Guessed by /u/Kyraryc A type of sword. Used by a protagonist. Female wielder. Modern/slight future setting. From Sword Art Online.

3) Soul from Soul Eater. Guessed by /u/Hyteg Has magic/powers. Can change shape/form. Used by main protagonist.

4) Pumpkin from Akame Ga Kill. Guessed by /u/RadioactiveSpoon Gun. Has magic/powers. Used by a protagonist. Female wielder. Alternate world, past setting. Dies in anime, not in manga.

5) 3D Maneuver Gear from Attack on Titan. Guessed by /u/Kyraryc Sword like. Used by a bunch of characters. Both male and female wielders. Alternate world, past setting.

6) Boosted Gear from Highschool DXD. Guessed by /u/lharb6 Gauntlet. Has magic/powers. Can change shape/form. Used by main protagonist. Male wielder. Modern setting. Dies, but is brought back.

7) Rory Mercury's Axe from Gate. Guessed by /u/King_Of_What_Remains Axe. Used by a protagonist. Female wielder. Part modern setting, part alternate world past setting.

8) Ser-Veresta from The Asterisk War. Guessed by nobody. Sword. Has magic/powers. Used by main protagonist. Male wielder. Alternate reality, modern setting.Originally a light novel. Adapted to manga, then anime. Light novel and manga appear to be still going. Anime is not.In the anime, the blade color is purple.

Remaining shows (6 and 8) are both on CrunchyRoll.

No show is repeated. Not from Bleach. Not from Fate series. Not Naruto. Not from Claymore. No shows from 2000 or before.

4 is the only firearm/gun. All others are some sort of melee style weapon. No spears. No knives or daggers. No mock weapons. (ex: kendo sword).