FFX riddles

[ReloadPsi]

Jecht sacrificing himself to become the Fayth to Braska's Final Aeon.

Should i stay or should i go
should i stay or should i go now
Self-explanatory

if i go then i will fall
Lose his corporeal form, effectively dying

so should i stay within these walls?
Sin

and let the master take my place
Auron, who's been helping Jecht learn about Spira, taking his place as Tidus' foster father of sorts

for sacrificing one of the same race
Again, self-explanatory