oh my gosh, this is a very easy eventing process.
Nobody even bothers to even try using the events anymore, it kind of saddens me.
Make a common event thats set to a switch trigger and put the events in it.
<>Conditional Branch: Hero [hero name] [Weapon] equipped
<>Change Skills: [hero name], + [New skill]
<>
Else Handler
<> Change Skills: [hero name], - [New skill]
<>
: End