During The Sealing Of The Chaos And The Creation Of The Universe, Arceus created 7 Universal Forces that spilted the heart of the universe. Afraid that Darkrai could take them all from Arceus in one attack he gave 6 of them to diferent beings. Space was given to Palkia, meanwhile Time was given to Dialga and as well Corruption was given to Giratina. Spirit was given to Cresselia and Arceus kept himself Light. Dark was thought to be given to the current Dragon Master but Darkrai intercepted the ritual and got it. Finally the last energy was the Mystic which Arceus sealed within the entrance of Dragon's Paradise.
Later on LDP 8 When Auraldo was about to give the energies back to Arceus, Zetdes appared and gave each of the 7 Energies to his 7 Servants, The 7 Demon and stroke Arceus with a Soul-Paralizing Wavelenght. Zetdes did this on purpose so when Auraldo came to fight with him, Auraldo will have the 7 energies on hand and it would be more easily to Zetdes to perfom the Ritual to open the gate to the Chaos.
If Arceus has the 7 Energies it's posible to him to destroy or manipulate the entire universe as he desires.
If Zetdes has the 7 Energie it's posible for it to reopen the Gate to chaos
A single energy let's that being manipulate that power.
Having all energy gives the user comand of these 7 energies but with limited uses.