Complex sentence: Firstly, we should not underestimate someone, as the deer did to Kelomang, and secondly, we need to be smart when someone underestimates us, like Kelomang was.
Split into simpler sentences: Firstly, we should not underestimate someone, like the deer did to Kelomang. Secondly, we need to be smart when someone underestimates us, like Kelomang was.