Thetis does not promise anything, but Zeus does promise Thetis that her son Achilles will be honored.
Achilles.
No, Achilles is the son of Peleus and Thetis.
Thetis largely helped her son Achilles achive his wish of glory.
Peleus, son of Aeacus.
Thetis gave prophesy that she would have a son greater than his father; Zeus and Poseidon did not pursue her afterwards but made it so she would have a son by a mortal. That son was Achilles.
Achilles is her son. Thetis was by prophesy destined to bear a son greater than his father (Peleus); Achilles was also prophesied to die if he went to fight in the Trojan war.
The prophesy which stated any child of Thetis would be greater than his father.
Thetis could be whatever shape she chose, the ancient Greek goddess was a Nereid and shared her father's traits for prophesy and shape changing.
Thetis is a Nereid goddess of ancient Greek myth, she has the power of prophesy, she can shape shift and has all other powers of a goddess of the sea.
Thetis does not promise anything, but Zeus does promise Thetis that her son Achilles will be honored.
Achilles
Achilles.
No, Achilles is the son of Peleus and Thetis.
Thetis largely helped her son Achilles achive his wish of glory.
Peleus, son of Aeacus.
Thetis is loyal and loving to her son, honoring what he wants to be above what she foresees as his fate.