>1) Run around and gang people down with a warrior or healer or
>whatever taking the front. Not really an option for me.

Yep, that's one way to do it.

Or if you're averse to ganging per se, think of it in terms of group vs. group fights.

>2) Surprise them when they're fighting mobs or other
>characters. Okay, that's possible (sometimes).

That's mostly the way I tend to do it as a lowbie/midbie PKing invoker. Run up on a leveling group before they see you and hose one or more of them straight down.

This is, in part, an exercise in knowing your enemies, and not just their vulns and such. As an evil invoker, you probably are not surprise killing a level 20 storm paladin that's tanking for a group because protection and haven are going to eat into your "flash kill" ability significantly.

At higher levels, consider this in the context of cabal raids too.

>3) Use some kind of mercenary/construct.

Possible, and you even have a blinding spell to go with it. Generally I don't think it's worth the rounds to rescue.

>Others that I'm missing? Right now if I see a warrior coming
>after me I'm likely to expect to get my ass handed to me.

And you're probably not wrong. Low/mid invoker running solo IMHO needs to think like an ambush predator.

If PK is still a struggle for you, honestly, invoker might not be for you, or you may want to shift your mindset to it being a character that's more for exploration for you than PK. I will say it's a great feeling to run up on a group killing trolls or dwarves or whatever and kill two of them with fireball before they know what hit them.