Materials: Blotstone, Deafstone, Memory Crystals, and Whisper Leaf:

The Ascended Isles of Serseki is not a realm one would typically expect to bring items away from, as the Hundki intends for it to be available to all who wish to ascend, however, some things which grow there or exist in abundance may be of great use to those that discern their value.  Chief among these are Blotstone, Deafstone, Memory Crystals, and Whisper Leaf:

Blotstone is a type of rock that occasionally flies out of the torrential winds under Serseki to either imbed into the floating islands' structure or land on its surface.  It is a highly compressed mixture of stone and biological matter, its center densely filled with a soft tar-like substance that, when the blotstone is heated, pours out of even the smallest crack slowly as pitch-black ink.  One cubic inch of blotstone has 2 EP, 1 Toughness, 1/100th lbs, and 1/8th gallon of extractable ink.  As a result, they are highly sought for academics seeking a portable source of ink, or used by rogues and other individuals for stealthy purposes.

Deafstone is a type of rock that is found easily in Serseki, being one of the primary materials used to make the temples and much of the structure of the islands themselves.  By themselves, they have 4 EP, 1 Toughness, and 1/450th lbs per cubic inch, as well as providing +5 Stealth against making noise at a cost of -5 Observation to noise, within a 7 square radius.  Additionally, if one charges them with 2 FP, they will temporarily invert it to provide -5 Stealth against making noise with +5 Observation to noise at a cost of 1 SP damage if sensitive to sound or if the sound is itself of noise-pollution levels and one does not shut it off within two turns.

Memory Crystals store the lifespan of one individual thus far into them, growing in Serseki under the many temples, being able to harvest the tips of to seed more memory crystals or use for storing one's memories.  If a character uses 5 FP while holding one, all of their memories will be copied into it.  If one uses 1 FP, they can replay any one day from a crystal in one minute's time.  If one uses 25 FP, and is able to put themselves into a day-long coma with no EP or FP regain during it, withstanding 10 HP damage, they may download all of it into their own mind and clear the memory crystal entirely without losing the memories.  If they wish to clear it without downloading it, they may submerge it in water for a day, letting it dissolve and form a new memory crystal.

Whisper Leaf is a type of material that rustles lightly in the wind, repeating all that it has heard within 5 squares through the past two hours if the wind did not rustle the leaves too much.  Whisper Leaf may be made into many different items as long as it can still rustle later, making it very useful for espionage, or just simply keeping track of conversations.  It does, however, take as long for it to repeat what it has heard as it takes for it to hear it.  Each cubic inch of it has 1 EP, 1 Toughness, 1/4500th lbs, and can work as well as larger quantities can.  However, strategic placement of more than one cubic inch makes it more useful if more is used.