Requirements:
Keen Talics (as many as you can, get in crag mine lazuardians or process ores+1+2+3+4)
Go to this NPC and exchange your talics to a box
You will get a 1 Blessed Mysterious Box, Open it.
You need to look for a "Leon Part Box" because the box gives all kinds of exp pills and keen talics.
When you open this box it gives a Random Leons Piece 1,2,3,4.
To make a Leon Weapon you need to complete Leons Piece from 1-4 and you need 1 pcs Blueprint.
Go to hero NPC, Combine all the appropriate Leon's pieces
Result is random you can get Low Leon Stats Medium or High Leon stats with random slots.
Example:
Low is 20
Mid is 25
Perfect is 30