The sword would proc very few times on private servers and the chain lightning damage would only hit the main target, not the other targets dealing around 300 damage. The threat generation as well on the jumps were not accurate.
heres some sources of how it was back in the day.
video source: https://www.youtube.com/watch?v=Ttbfhwv84EY / http://www.warcraftcinema.com/001200620 ... .movie?u=9
patch source 2: http://www.wowwiki.com/Patch_2.0.10
***Bc icon Patch 2.0.10 (2007-03-06): The threat generated from the proc has been substantially reduced. The threat generation from a proc of Thunderfury was previously equivalent to that of approximately one application of Sunder Armor from a lvl 60 warrior.***
Source 3: http://www.wowwiki.com/Talk:Thunderfury ... Windseeker
Any ideas or information on actually replicating the "legendary" weapon that it was back in vanilla wow accurately? I wouldn't want to see any guilds acquire this weapon only to have it be worthless like it is on other private servers.
