In the campaign for beyond light I used voidwalker with blink, during the campaign portions where you got to use stasis powers, it let me use blink while using them, which is how I was able to use blink with Shadebinder. Personally, I just want pre 3.0 phoenix dive back. It was a much better ability back then. I think that placing a rift just to run out of it with an arc soul is a little counterintuitive, so I'd rather an ability more tailored to the aggression the subclass has. The chaos reach buff you suggest could also work. Stormcaller was originally told that amplified buffing abilities was "their thing" as of now only melee and arc soul is buffed by being amplified. I think it's fair for it to buff grenades slightly and buff supers too considering that. I mostly just want lightning surge to do more than just give you an alternate melee. I'm open to something else as a small buff to it.