METATRON'S PROFILE

As long as it's hinted at at least vaguely, isn't missable (or isn't important), and is rewarding, I have no problem with insanely hidden stuff.

Zodiac Spear was none of those.
The Red Gems (Illusion of Gaia) were all three.
The sword at the end of FFIX was all three.
Gold Chocobo was all three.
Aerith's last Limit Break was all three (actually it's all four since you can still get it after she dies).
Most of the special photos in Dark Cloud 2 (and the prizes associated with them) were all three.

I could go on and on and on, but it's been covered pretty effectively already.