It wasn’t something she noticed right away.
When she did notice, when she realized what it was, it made her sick to be in her own skin.
She hated herself for it, for what Hama had forced her to do with her bending. She hated how achingly powerful it made her feel, to be able to have the pulse of the older woman beneath her fingertips without even being within arm’s reach. To be able to feel the skittish rattling of Aang and Sokka’s hearts ricocheting in the back of her throat, even if she didn’t reach out for them with her bending.
It’d been a creeping sensation sliding beneath her skin ever since encountering the old waterbender, but it wasn’t until they were on the way the Western Air Temple that the full weight of understanding sank into her like a heavy stone to the bottom of the ocean.
Katara could still sense the pulse of not only Aang and Sokka, both of whom she’d felt under Hama’s control, but the blood of everyone around her. It shifted and thrummed at a low, low level, like undercurrents beneath the stronger tide. The same way she could feel the siren call of the dark depths of the ocean, the muted beats of pulses not her own called to her, tried to lure her down to them.