Thundering Greatsword +1

Description:

You can unleash a clap of thunder when this weapon hits, carrying your foe away on a wave of deadly sound.
Lvl 3, +1
680 gp
Weapon: Any
Enhancement Bonus: attack rolls and damage rolls
Critical: +1d6 thunder damage per plus
Power (Thunder) Daily (Free Action)
Use this power when you hit with the weapon. Deal 1d8 thunder damage and push 1 square.

Found in the battle against the possessed wizard Ladon

Bio:

Thundering Greatsword +1

The Loudwater Chronicles rabies66