The logic might have to change a little for it to work in the legendItemHover
event instead. When changed to be fired then, it works as expected for the first series. The Dojo I shared with you was just a proof-of-concept to get you started.
The best event to restore opacity might vary depending on the requirements of each application; the process of restoring it would be similar to what we did using the series options for opacity.
If there's still something missing from your implementation of this functionality, please share a Kendo UI Dojo
that represents what you're currently working with so we can jump in and help you by editing it directly.
I hope this helps!
Telerik by Progress