Skill Duration passive - Lightning warp question

Yes

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EP723 wrote:

would a long duration lightning warp be useful and why?

Yes. The original design of lightning warp was based around this - you cast it at a safe location for a long duration, then charge into enemies and can play dangerously knowing you'll be pulled out (and damage them as you leave).

It's not as popular these days as just using it as an instant teleport, but it can still be done, and still be useful.