Callen has an ability where her negative emotions play a crucial part.
Her tears able to defy laws of gravity and hover around or over her head.
She can wipe them away in its liquid state with her sleeve or another absorbing surface before it leaves her cheeks.
Callen considers this ability to be a curse rather than a blessing.
Anger is often an additional side to her sadness. An overwhelming, cold sensation can emit from her and in the heat of the moment, her tears solidify.
In short: When Callen is mad and sad, her tears will do the stabby-stab.
Anything and anyone in proximity to Callen—even Callen herself—could become a potential victim.
In numerous cases, Callen’s nuisance is usually herself. Thus, she tries to find things to be happy about, even if it’s small.