News #1147 posted by An escaped demon on 03/29/20.

Through the suffering brought on our kind by the Demon Hunter of Midway, a rift
has opened. Though you have fought well and driven me back to our plane, other
demons escaped into your land.

Already demonblood has mixed with the one who struck the blow that drove me
back. Politelaris may have wounded me, but I have tainted his blood. Now
Merihem his spawn, has the mark of demons upon him. For now, he is the
only one of his race but soon we will spread our presence further.

HELP Tiefling will tell you more.