This technique applies cursed energy to the user's target using a straw doll as an effigy.
The user will generally use one body part of their target to create the link and then use resonance to apply damage to more critical appendages of the opponent's body. For example, by placing a curse's severed arm on the straw doll and striking it with a nail using a hammer, the nails can be used to pierce the targeted curse's heart.
The effectiveness varies depending on the opponents skill level, the targeted body part, and the strength of the connection to the user's target. If a link is made to multiple opponents, Resonance will injure them all at the same time. It also works on inanimate objects and can disrupt someone else's control over them.
Resonance is Nobara's signature move and her go-to attack when exorcising weak curses. She uses it to stop curses from fleeing, as she can exorcise them no matter where they are as long it's connected to her straw doll.
Using a single bristle from Momo's broom, Nobara was able to use Resonance to disrupt the third-year girl's control over her flying broom.
While infected with Rot Technique Decay, Nobara could pierce herself with her nails and inflict damage on both Eso and Kechizu. This was due to their connection to her blood via the aforementioned Rot Technique.
Resonance proved to be the perfect countermove for Eso's Decay, as she used it over and over again to stun both brothers until Eso was forced to deactivate his technique. When Eso attempted to flee, Nobara used Resonance on his severed arm to injure him and stop his escape.
During their fight in Shibuya, Mahito initially believed Nobara would have no way to hurt him, as traditional techniques cannot injure his soul. However, by striking Mahito's body with Resonance she could attack his soul directly. Nobara did so by hammering a nail into Mahito's forehead and activating her technique.
Resonance's activation on Mahito's double relayed the effect to his main body, causing spikes to erupt from his chest. This stopped Mahito's main body from fighting Yuji elsewhere. Then the damage Mahito's main body received relayed back to the double, severely injuring both of them. After this, Mahito immediately considered Nobara his natural-born enemy just like Yuji.