ok, the door near the library requires a reversal of thinking, and that's the final temple. The temple in the forgotten city is for assembling the tablet. Other than that, you're good to go. You've met the bard, right? :D
I finally found the final temple, but the combination doesn't seem to make sense to me.
First combanation is 1-2-3-4. 3 and 4 are raising their arms outwards. (3 is raising right arm while 4 is raising left arm)
And the 'reverse' combination seems to be 4-3-2-1. 4 is raising left arm, 3 is raising right arm. So this time, they should raise their arms inwards like they're reaching for each other's hands. And I've tried this combination before writing that reply.
But the real combination is 3-4-2-1. They're raising their arms outwards again.
Or another reverse combination might be 3-4 / 1-2 (reversing the 2 blocks). But it doesn't fit to the real combination either.
Hello there! The second combination is not actually the reverse order of the first one, but the order in which the statues stop before opening the first gate. When you solve the puzzle, they move until they stop and then they move again. The order in which they stop is the key for the second gate.
Hope this helps!