If you want to complete the test to reach level 7 you will have to kill:
* 20 Serena
* 15 Gunga
* 15 Guradoz (monster of about -30.000hp)
* 10 Octalus
* 10 Tortugas
This all has to be managed in 2h.
A Guradoz can only be found in level 5 and up. Their hp is about 25.000 to 30.000. Takes a while to kill them.
Good luck to all.