Why does Tirana of the Celestial Bastion require so much fervor?

[HoboRockBox]

Is it a good prayer? Is there any reason it would cost more than Debla of the Lights?

Personally I've never used it because it doesn't seem worth the cost

[Boksha]

Some of the balance in this game doesn't really make sense. Maybe it was made so expensive because it's quite easy to get (you just need to buy the key to get Blood Perpetuated in Sand and climb up from there), but even so there's basically no place where this prayer is ever a good choice given its cost, how little damage it does and how quickly the barrier disappears. It's just a really bad prayer.