I am still a firm believer that the Tai-Na, the walking islands of the Reshi sea, are later stages of chulls.
The reason - or at least my explanation of why - most chulls aren't becoming Tai-Na, is that they need to pupate in a specific area to metamorphose the second time. Like chasmfiends has to pupate on the shattered plains, and larkin has to travel to Aimia to grow.
The primary evidence against my theory is the number of legs. Both larva and adult chulls have six legs, and Tai-Na seem to have many more.
All shellbeasts do pupation and metamorphosis, though, so the number of legs is not a strong as argument as it might seem. How many legs do larva and adult butterflies have?














