Item opinion

I'm in the works of making a custom item and Im looking for some constructive opinions.

Version 1:

This flawless katana bears the mark of Taka Kobe, an honoured swordsmith of Kara-Tur, though how it came to be here is unknown. Perfectly balanced, the kensai can let the momentum from a deadly melee attack carry his weapon into another foe, thereby gaining an extra attack per round.

STATISTICS:

Combat abilities:
- 1 extra attack per round (Kensai)

Damage: 1d10+2 (slashing)
Speed Factor: 0
Proficiency Type: Katana
Type: One-handed
Requires:
6 Strength

Weight: 4

Version 2:

This flawless katana bears the mark of Taka Kobe, an honoured swordsmith of Kara-Tur, though how it came to be here is unknown. Perfectly balanced, a kensai can let the momentum from a deadly melee attack carry his weapon into another foe, thereby gaining en extra attack in the next round.

STATISTICS

Combat abilities:
- Whenever the wielder delivers a killing blow to an enemy, gains an extra attack in the next round (Kensai)

Damage: 1d10+2 (slashing)
Speed Factor: 0
Proficiency Type: Katana
Type: One-handed
Requires:
6 Strength

Weight: 4

I was planning to imbed it into the game by assigning it to a kensai enemy...