Excalibur

Excalibur is a legendary wind magic used by Merric in Fire Emblem: Ankoku Ryū to Hikari no Tsurugi, Fire Emblem: Monshō no Nazo and Fire Emblem: Shadow Dragon. It later reappears in Fire Emblem: Rekka no Ken as an S-ranked Anima magic tome (where it is known as Gigascalibur in the Japanese version) and in Fire Emblem: The Sacred Stones as one of the Sacred Twins of the Jehanna royal family. The spell itself conjures wind blades to attack the enemy. The Fire Emblem: Thracia 776 spell Grafcalibur, the Fire Emblem: Fūin no Tsurugi spell Aircalibur, and the magical Wind Sword are considered variants of Excalibur.

Although the Tellius Series spell Rexcalibur appears to be a variant at first glance, it actually bears a closer resemblance to Fimbulvetr.

Ankoku Ryū to Hikari no Tsurugi
Weapon Type: Magic Weapon Rank: Prf (Merric only) Mt: 13 Hit: 100 Crit: 20 Range: 1-2 Uses: 33

Fire Emblem Gaiden
Weapon Type: Black Magic Mt: 5 Wt: 1 Hit: 100 Crit: 20 Range: 1-2 HP: -3

Monshō no Nazo
Weapon Type: Magic Weapon Rank: Prf (Merric only) Mt: 12 Hit: 100 Crit: 30 Range: 1-2 Uses: 25

Rekka no Ken
Weapon Type: Anima

Weapon Rank: S

Mt: 18

Hit: 80

Crit: 10

Wt: 13

Range: 1-2

Uses: 25

It can be obtained by killing Ursula in the last chapter. She appears in the fifth room opened along with Jerme.

The Sacred Stones
Weapon Type: Anima Weapon Rank:S Mt:18 Hit:90 Crit:10 Wt:13 Range:1-2 Uses:30 Effect: Speed +5

Shadow Dragon
Weapon Type: Tomes Weapon Rank: B Mt: 13 Hit: 100 Crit: 20 Wt: 1 Range: 1-2 Uses: 33 Effect: Males only, Effective versus flying units, Merric can wield at E rank

Etymology
Excalibur is the name of King Arthur's famous sword. Usually a distinction is made between Excalibur, which he receives from the Lady of the Lake, and the sword which he pulled from the stone to prove his kingship. Thomas Malory, author of 'Le Morte d'Arthur," says that the name Excalibur means 'cut-steel.' Earlier versions of the name include Chaliburne, which evoke the French word 'chaleur' meaning 'heat' and the English 'burn,' which either means 'burn' as we understand it today, or 'man.'   At Arthur's death, he had his last remaining knight throw Excalibur into the sea, where the Lady of the Lake caught it and took it back.