Almighty Summoning Piece Icon
"It's a blank scroll. It can replace up to 25 monster pieces of 4★ or below monsters."

The Almighty Summoning Piece is an item available in the Guild Shop. It costs 200 Guild Points for 5 pieces. These pieces can be used to replace up to a maximum of 25 Summoning Pieces of any monster that is 4-Star or below. A prerequisite is that you will need to own a particular monster's Summoning Pieces before being able to use them. 

For example, if a player has gathered 47/50 Summoning Pieces for Sylph (Light), he could purchase the Almighty Summoning Piece x5, and use 3 of them as Sylph (Light)'s Summoning Pieces. The remaining 2 pieces will be stored in the player's inventory, and can be used at a later date. 

If however, a player only has 24/50 Summoning Pieces for Sylph (Light), due to the limitation of only being able to replace with up to 25 pieces, the player can only end up with a maximum of 49/50 and will not be able to summon the monster.