After finishing a story playthrough, you unlock the option to play on Mayhem Mode for that character. Mayhem Mode causes all enemies and equipment to scale to your level but also makes your enemies significantly stronger and introduces random modifiers that affect gameplay.
One of the hidden Mechanics of Mayhem Mode is that certain things gain additional damage the higher the Mayhem level is that you choose to play on. Most importantly things that aren’t directly affected by your gear but only your character level, such as melee damage or action skill damage.
This leads to some interesting results, such as some things being up to 33 times stronger on mayhem level 10 (which is the current maximum, though a Mayhem level 11 is going to be released on November 10th) than they are on regular level 65.
For Amara specifically that means that if you have Ties that Bind and you phasegrasp an enemy, the enemies connected to your target will actually take considerably more damage than even the primary target.
I’m not an Amara expert by any means, but I have seen bosses getting one-shot because the player had TTB and picked up one of the bosses minions.