This WHM/BLM/BRD Attestation NM is found in the central tower of Beaucedine (near outpost npcs in the non-Dynamis area). He comes with 6 buddies (2 Hydra BLM, 2 Hydra WHM and 2 Hydra BRD). Quiebitiel has all 3 2hr abilities and can use them more than once (multiple Benedictions can make this battle last a while since he has around 20,000HP). He can drop 1 of 3 possible attestations: Sacrifice (club), Harmony (horn), or Celerity (dagger). He is one of the easier attestation NMs (easier than the DRG/SMN/BST or MNK/NIN/THF ones for sure).
And to correct the info, he does NOT drop the Atst. of Force (great axe). The Atst. of Force is dropped from Goublefaupe (the PLD/WAR/RDM NM in the northern tower in the quadav area)