Question: how to recruit zihark path of radiance?
Answer: Zihark can be recruited to Ike's party if he talks to Lethe or Mordecai in Part 3 Chapter 6. He can also be recruited if he is talked to by Lethe or Mordecai, or by Brom or Ilyana with an A support in Path of Radiance in Part 3 Chapter 7 and Part 3 Endgame.