some years ago (3 years more or less) I used to see a Anime series that is very similar to pokemon. There was a young boy (the protagonist) who knows a "crazy" professor (also with white hear) who shows him a world of monsters that he can control to fight. I can't remember any more because I only saw the first episode.
The fact is that of that anime series exist a online PC game. Where you have a character that you can move where you want over the world. The player can have only 3 monsters at time going everywhere with him. Also I remember that these monster have only one especial ability (for example there were owls that can heal), also you can combine this monster in order to have a beter one. Some of other kind of monsters I remember was some type o witches and may be some monsters like animals.
Please help me to know which series and game I talking about, Thanks a lot.