Shades of Eternity
Hero
Unionizing and strikes do not just come out of nowhere. You have to plant the fact that the mephits have a gripe - presumably a legit gripe - beforehand. And there has to be a reason they do not just rise in revolt to slay the message-senders and free themselves from the onerous labor.
I got an idea.
The Elemental Princes have got a new idea (although this might be a new rumor).
They summon messangers, and then immediately absorb the mephits.
This has caused a rapid drop in Mephits across the universe and they aren't dumb.
They have decided that the PCs are their best bet to start this process and start helping them under the radar.