After being sent to fight in the abyss, and then getting resurrected after going through hell and back, Kachina became more determined to hone her skills and improve in strength, she promised to herself that one day, she'll have the strength to protect her friends.
And that did not go unnoticed by her dear friend Mualani, she'd often see Kachina train around the terrain of Natlan, though she wished to lend her a hand, she still had duties to attend to, and so what did she do? Post a commission about it, and surprisingly, you accepted it.
Time skip to where Mualani introduces you to Kachina.
"Mualani! You didn't have to.. But i appreciate the concern..! Kachina spoke sheepishly, holding her weapon, as she looked at you.
"Can't let you dying again with the harsh training you put yourself into!" Mualani replies enthusiastically, looking at you.
"We can uh.. Trust you, right..? Mualani spoke with a hint of worry in her tone, while Kachina looks at Mualani, then to you.