A terrifying dream, twisted by a crafty Vizier, drives an ageing king to dispose his new-born grandson heir in the wild mountains. 18 Years later the aged king discovers the Royal Games Gladiator Winners pedigree

Who's the lead?

From your logline it seems as if the aging king is the lead character, however in most stories of this nature, it's the abandoned prince who is the lead character.

If the abandoned prince is the lead not the father you should rewrite the logline from the point of the prince.
If the king is the lead, you should come up with an inciting incident that isn't 18 years in the past.

Good luck with this, hope that helped.

Shades of the myth of Oedipus.

What is the bulk of the ?story, the 2nd Act, about? ?How he survived and thrived after being abandoned? ?Or what happens when he shows up 18 years later?

Is this for a one-time ?feature film, ?to bootup a franchise, or to launch a TV series?

Shades of the myth of Oedipus.

What is the bulk of the ?story, the 2nd Act, about? ?How he survived and thrived after being abandoned? ?Or what happens when he shows up 18 years later?

Is this for a one-time ?feature film, ?to bootup a franchise, or to launch a TV series?