The sapphire tuning fork isn't a key—it’s a . If the party uses it to "kill" the Lich, they realize Zephyrus was actually holding back an even greater threat: a Kraken of the Stars trying to break into the world through the desert. Why this works:
Do they kill the Lich and risk the Kraken, or help the Lich stabilize the city?
The party only has until the eclipse ends (roughly 4 hours of in-game time).
Success saves the region; failure expands the desert.
The final confrontation. Zephyrus fights by manipulating gravity and summoning "Memory Phantoms" of the players' past enemies.