Ravenloft

What we know

Iron gates into Barovia flanked by headless guardian statues; shields carved with a raven crest (Session 2 @ 02:52:20)
Raven crest marks the von Zarovich ruling line, which includes Strahd von Zarovich; party found the crest unfamiliar on first viewing (Session 2 @ 02:55:21)
Saturno's history check read the artwork as a ruling-family crest but could not identify it (Session 2 @ 03:08:13)
Related to Castle Ravenloft, seat of Strahd von Zarovich (Session 2 @ 03:26:26)
Dungeon cult at Durst Manor chanted "He is the ancient. He is the land."; scrying orb whispered the dark lord's eyes are watching (Session 2 @ 00:32:15)

Strahd von Zarovich — Lord of Barovia; seat at Castle Ravenloft (Session 2 @ 03:26:26)
Rahadin — traitor; serves Strahd; also member of Dusk Elf (Session 9 @ 01:48:15)
Escher Belasco — Strahd's cupbearer; met as "Abraham" at Kolyan Indirovich's funeral (Session 5 @ 01:29:24)
Volenta — one of Strahd's brides; led false Court of Wolves eliminating threats to his rule (Session 18 @ 02:14:56)

Gates opened and closed on their own as party passed through (Session 2 @ 03:03:20)

Unconfirmed: whether party connects gate crest to Strahd von Zarovich by name (Session 2 @ 02:55:21)