Ilyasa' was the faithful student of Prophet Ilyas. From youth he accompanied Ilyas in his mission, learned from him, and witnessed many events. When Ilyas grew old, he appointed Ilyasa' as his successor.
After Ilyas passed away, Ilyasa' continued the mission to the Children of Israel. Many of his people had strayed. Ilyasa' patiently called them back to Allah.
What's special about Prophet Ilyasa': he doesn't have dramatic stories in the Qur'an. He's only mentioned in two verses. But Allah praised him: "And remember Isma'il, Ilyasa', and Dzulkifli. All were among the most excellent." (Sad: 48)
For children: not everyone Allah loves has a dramatic story. Many of His special servants are special precisely for unflashy persistence — done every day without drama.
Several generations after Ilyasa' died, most of the Children of Israel grew even further from Allah — until finally Allah sent the next prophets: Yunus, Zakariya, Yahya, Isa.