Responses
SPOILER
Yes, one appears in the future and became a follower of Pyo Wol after his companions are killed and Pyo Wol helps him. The other two are working together for an assassin's company. There are another that tries to kill MC but ended up badly.
28 children were sent and 24 died, one of which is mc so the other 3 in the cover must be still alive (≧∀≦)