Kechi's Soul Stone
Soul Stone obtained from defeating Armed Kechi. When combined with Veridan's Soul Stone and Michaela's Soul Stone, it will be turned into a Dark Soul Stone. Take it to Head Priest of the Earth Daichir to be recognized for defeating Earth Wyrm Trasken.
Not dropped by monsters.
Cannot be spoiled.
The chances are official (x1). On servers with x10, x100 and higher rates, drop and spoil come more often.