One of the additions to To the Tops of Timewhose purpose is to enable teleport on 2 different islands. You can do this by activating 3 of the same seals on the map, but there is a catch: when you defeat an enemy, part of the platform is removed.
There are 2 types of seals:
Moon seal
Leads to a crystal chest containing Shemira.
Solar Seals
To find all solar seals, just follow this path:
This will activate the teleport in the center of the map:
After becoming on the teleporter, you will be taken to an island where there is a crystal treasure chest containing 20 fragments of Dur's grace:
Moon Seals
To find all the lunar seals, follow this path:
As with the first seal, this will activate the teleporter in the center of the map:
Stand on it and you will reach the last island with a crystal chest with an epic shemira: