I've checked and ... seems /use actually "equips" item rather than invokes "use" script. So it probably wouldn't work. But I can readily propose couple of other things to invoke scripts for item anyway. Like e.g. NPC or chat spell.
Either way... since you've told it's okay, I've transferred effect on top of "mainline" resources, using 04159cdc6ad594360a2af607b6587086fa2ccbe3 (your Xakelbael fix) as starting point. I've put it here - https://notabug.org/hello.tmw/tmwa-client-data.git (browsable as well). You're interested in branch dark-talisman-fx - commit 5b8711da19a5654dd39ac2e6fd89c75d498fbba2 (I'm sorry for some hex-speak).
I've gave it a try "locally" and it seems to work fine but it's 1st time I try this so I wonder if it's possible to test that on testing server before pushing on everyone else heads? Well, the only thing test server should do is to give out "newer" zip, there're no serverside changes. But I'm not sure if testing server uses same update host & zip as main or not.
Additionally it fixes Dark Talisman description (Def +30 -> M.def +30, Dark Talisman doesn't affects def at all). Credits for this are going to Ledmitz.