Sareth did not think about escaping but stayed at Nero's house temporarily.
First, he knew that he could not defeat Dante and the others, and if he ran away, they would most likely catch him again. Second, he subconsciously recognized them as his kind after confirming Dante and Nero's identities.
With Nero and the others, the feeling of estrangement that Sareth had after entering the human world disappeared a lot. Sareth was only a child, so of course, he did not like being alone. Now that he had people to talk with, he was naturally willing to communicate.
Nero's garage was also Nico's workshop. There were many things that Sareth found strange here. Out of curiosity, he kept asking Nico questions, and she patiently answered them. She even showed him the use of some of the tools and let him try them personally sometimes.
