The 4 Prince -I.Series_

After taking possesion of the 3 main prince (Sea,Nature and Stars) the Deoxys wanted more:they would use them to capture the Prince of Life,Mew,which is said that carries the power of all the Pokemon in the world,making it the most powerful of them all.
The battle took place at the Sacred Tree of the beginning.Mew where expecting them,and the battle started right away.
However,the "Prince of life" had a power beyond their imagination.The 3 infected Prince where having trouble trying to defeat Mew.
A Deoxys was waiting on a corner,waiting for the perfect moment to take over Mew's body and his rich-in-power DNA.

After hours of Struggle,Mew layed on the floor,defeated...

Or wasnt he?

Deoxys took the chance and flew where the Prince was.So it started to enter through Mew's wounds...
The whole body turned orange and green.But as soon as Deoxys tried to enter Mew's mind to fully control him...something happened.

Mew wasnt defeated at all! He let Deoxys enter just to imprison him in its mind and body,taking the Alien DNA and powers for him to control!

The three Prince stared at Mew,while he flew away,dissapearing through a blinding light.
Why Mew flew and didnt stay to release them from the Deoxys? who will stop the Infection/invasion then?