No existing method for Vellum Katzbalger effect

[b]Origin:[/b]
[url="http://herc.ws/board/topic/2138-help-with-vellum-kaltz-script/"][url="http://herc.ws/board/topic/2138-help-with-vellum-kaltz-script/"]http://herc.ws/board/topic/2138-help-with-vellum-kaltz-script/[/url][/url]

[b]Description:[/b]
Currently, it appears that there is no proper way to execute the effect of the weapon, Vellum Katzbalger, which states that it "Drains 8% of other players HP for each non-skill attack."

[b]Sources:[/b]
[url="http://forums.warpportal.com/index.php?/topic/89159-bellum-kaltz-nerf/"]WarpPortal discussion about nerfing the existing effect[/url]
[url="http://db.irowiki.org/db/item-info/21002/"]iW Database entry for Vellum Katzbalger[/url]
[url="http://ratemyserver.net/index.php?page=re_item_db&item_id=21002"]RateMyServer.net database entry[/url]

[b]Proposal:[/b]
[url="https://github.com/HerculesWS/Hercules/pull/90"]Create a bonus2 command called [b]bHPVanishRate[/b][/url] in the same format as [b]bSPVanishRate[/b], which already exists.