Vassal Claw

The Vassal Claw or Seven Star Claw, also known as the Claw Spirit of the Vassal Weapon. The spirit is from another world prior to being summoned to another world, the Vassal Claw is one of the eight Vassal Weapons present in the world which Naofumi currently resides in. The candidates of the weapon have been given the title of Claw Hero, whom they are generally addressed as so by the locals. The current candidate of the Vassal Claw is unknown.

Overview
During the time of the shield hero Mamoru. The vassal claw was wielded by Filolia, a girl with a chunibyo personality on a high level. She was from the S'yne world and belonged to the skywing race, during the battle that Mamoru and his allies had against the Phoenix, she sacrificed herself to protect them and her soul was taken by the guardian beast. After that the spirit of the claw wandered around the world without choosing any new user, until with the help of the heroes of the future they managed to bring Filolia back and thus the spirit of the claw returning with her.

The first known Vassal Claw Hero is Rhubaldt, a werewolf demi-human of Siltvelt. However, sometime after the four Legendary Heroes were summoned he was killed and had his weapon taken by Takt. Tulina used illusions to take his place but was discovered by Naofumi and Raphtalia.

The Vassal Claw was first seen as the favoured weapon of Takt during his conquest of Raphtalia's World. He used this weapon to "kill" one of the Phoenix birds which caused a devastating explosion for the heroes. He also used a cursed attack from the Vassal claw to kill Queen Mirellia Melromarc and greatly injure Naofumi. However, Takt was eventually defeated during his conquest and Naofumi used his authority as a Holy Hero to strip Takt of all seven stolen vassal weapons. The Vassal Claw flew away among with some other weapons and has not been seen since the fight with Takt

Power-up Method
The power-up method of the Vassal Claw is "Skill Mastery". The more a skill is used, its levels and abilities are improved. Improvements include reducing the required SP, change the effects of the skill, increase its damage, or reduce cooldown time.

Trivia

 * In the Web Novel, Filo wielded the Vassal Claw.