Langrisser II/Weapons

Knife

 * +1AT
 * 50P
 * "A knife for self defense."
 * Not usable by: Clerics

War Hammer

 * +2AT
 * 120P
 * "A curved war hammer."
 * Not usable by: Mages

Great Sword

 * +4AT
 * 300P
 * "A large, heavy sword."
 * Not usable by: Mages, Clerics

Devil Axe

 * +8AT
 * -3DF
 * 2,500P
 * "A great axe infused with a strong enchantment."
 * Not usable by: Mages, Clerics.

Langrisser
The legend, the power, and the game.
 * +4AT
 * +1DF 0P
 * When powered up by Riana and Larna
 * +9AT
 * +2DF
 * "A sacred sword containing the power of both..."
 * Usable only by Elwin, Sherry, Jessica, Riana, or Larna. (i.e. Descendants of Light)

Masayan Sword
Doubles any experience gained through combat or healing. The end of scenario bonus is still the same. Masaya is the company that made Langrisser, and the logo described is indeed their logo.
 * -4AT
 * -3DF
 * -2A
 * 600P
 * "A sword with a logo of a horse and star..."
 * Usable by anyone.

Despite its negatives, this is one of the best items in the game. Favor whoever wields it by feeding them experience, and switch it off between characters in between missions. The cumulative effect is enormous.

One interesting bug for this is that if you give it to a character whose attack bonus is less than 2, it will interpret the -1 as a +55. This has no real application unless you're using the secret shop code, since by the time you can get this blade legit your characters will all have well above +2A, but it's kind of funny to abuse.

Note: Because of this item's negatives, I never bothered equipping it at first. I probably never would've figured out what this thing does if it wasn't for someone posting it on the GameFAQs message board. I don't remember who it was, and the message is gone now so I can't check... but whoever it was, thank you.

Dragon Slayer

 * +7AT
 * 10,000P
 * "A magical sword used by a dragon slayer."
 * Not usable by: Mages, Clerics

Flame Lance

 * +6AT
 * 8,500P
 * "A magical, flaming lance."
 * Only usable by: Knights, Sea knights, Sky knights.

Longbow

 * -2AT
 * -2MV all
 * 250P
 * Gives character ranged 3 attack.
 * "A strong bow made from the wood of a special..."
 * Usable only by rangers and highmasters.

Arbalest

 * -4AT
 * -2MV all
 * 1,250P
 * Gives character ranged 6 attack.
 * "A powerful crossbow."
 * Usable only by rangers and highmasters.

These two items are kind of a letdown, they come with heavy penalties and the ranged attack isn't really worth it. In fact, the highmaster and ranger classes in general were a bit of a letdown. You should probably give the swordmaster a devil axe then promote so you can have a highmaster with a decent attack rather than go with either of these.

Wand

 * MagicRange+2
 * MagicDamage+1
 * 150P
 * "A magical cane."
 * Not usable by: Anyone but Mages and Clerics

Holy Rod

 * MagicRange+2
 * MagicDamage+2
 * 4,000P
 * "The rod which is the key to unlocking the..."
 * Usable by anyone.

Dark Rod

 * MagicRange+2
 * MagicDamage+2
 * 4,000P
 * "The rod which is the key to unlocking the..."
 * Usable by anyone.