Corridors of the Time Palace: This has such an epic sound. I love the French Horns/brass and the choir. The flute melody is also very well-written. You have also mixed this very well and have the perfect amount of reverb. Excellent first track!
Keepers of Causality: I love how this track starts small but then builds to a colossal sound of brass. This is very cinematic and would work very well in an epic movie using the story you wrote.
The Fountain of Youth: I really like the panned clinking and wind sound effects. This is also an epic climax to your OST. My favorite part is the reversed effect on the French Horns at the end - so cool!
Overall: You have such a good idea for the story of your OST and it is well written in the description, and even more impressive is your ability to tell that story through your music. This is masterful work and I really enjoyed listening to it. Excellent job and thank you for sharing!