You must pursue Nabriales into the aetherial tear that he created in the Rising Stones, to prevent him from using Tupsimati.
How to Unlock
The Chrysalis trial is unlocked by the level 50 Main Scenario Quest An Uninvited Ascian.
First Phase
Nabriales will cast Spark on the player with the highest enmity.
Nabriales will sometimes cast Double, which causes Spark to be cast twice.
At around 80% health, Nabriales will go to the center of the area and become untargetable. Black orbs and red orbs will move toward Nabriales. Players should absorb these to prevent Nabriales from absorbing them, but be sure to alternate red and black orbs. Red orbs increase magic vulnerability and reduce physical vulnerability, while black orbs do the opposite. Collecting the same color of orb will place a stacking status ailment on you that will leave you more vulnerable to physical or magical damage, depending on the orb type.
There may sometimes be a red orb that looks slightly different. If a player or Nabriales absorbs it, it will turn into a Shadow Sprite, which will sometimes target a random player with a cone attack that extends the length of the area. The Shadow Sprite can be killed, but be sure to continue to gather orbs while you do so.
After the orbs stop appearing, Nabriales will cast Dark IV. The strength of this attack will depend on how many orbs Nabriales absorbed.
Afterward, Nabriales will continue to cast Spark and Double, and will also sometimes teleport to an edge of the area and cast End of Days, a long line attack across the length of the area. If you are hit by this, you will get a Suppuration status that reduces your maximum HP and increases the damage that you take.
Eventually, Nabriales will start casting Triple, which will make him cast Spark three times in succession.
At around 35% health, Nabriales will go to the center and become untargetable, and more orbs will float toward him. Absorb these as before, alternating between red and black. Afterward, he will cast Dark IV, which will be stronger the more orbs he has absorbed.
Nabriales will continue his attacks, with the addition of Quake III, which damages all players.
Second Phase
At around 20% health, Nabriales will cast Blight, followed by Extend, and will create a portal in the middle of the area. All players will be pulled toward it. Before you enter the tear, you may wish to cast beneficial spells on yourself and the party, because their duration will be greatly increased from usual.
Once you are inside the tear, tanks need to stand under the falling comets to reduce the damage that they cause to the party. If the tanks are unable to stand under all of them, other players should ensure that at least one player is standing under each one. After the first comet falls, an Aetherial Tear will appear where it landed, and all players need to attack it. A DPS player should use Limit Break on the Aetherial Tear, while all other players do as much damage to it as they can. If you do not destroy the Aetherial Tear before the large comet lands in the middle, you will be defeated and have to start over from the beginning of the duty.
After the Aetherial Tear is destroyed, players will be returned to the area, and Nabriales will resume the attacks from before. Continue attacking him until he is defeated.
Completing the Quest
Defeating Nabriales will complete one of the quest objectives for the Main Scenario Quest An Uninvited Ascian.