Swish!
Jumping out of the wall, Riya landed on the tree and used her illusion magic to hide her presence. There were indeed invisible magic, but that magic use too much mana and for Riya, an illusion magic was enough.
These magic beasts couldn't sense her presence at all.
'Should I kill them?'
Riya thought for a moment and then raised her hand. Magic runes formed in the air and then…
'Arrow tracking formation magic.'
Swish! Swish! Swish!
*roar!* *roar*
These magic beasts were killed in one shot. Riya conveniently picked up their corpses into her world and then departed away. She looked at the large number of magic beasts' corpses on the way and also picked them all up.
Most of these magic beasts were trampled by their own kin when they were running away. The magic beasts had no sense of guilt or anything like that for killing other magic beasts and when they had a goal, who would care about other things?