An Unfinished Story

Clare's soul is very mutable, an aspect of Clare's innate desire to please. Covering why transformation and matching wavelengths isn't really hard. Her innate desire when she is with someone else is to make them happy unless they have done something specific to her or someone she cares about, to change this desire. Even people she's on bad terms with she will attempt to be nice and kind to provided they are not being hostile or insensitive. So even with a new person, Clare's soul attempts to match their own wavelength pretty much subconsciously as Clare, when all is said and done, is a very nice and good person.

However, there's a big ol' caveat here, in that while she can match well with anyone her trust and self-confidence issues (mostly relating to trust) limit how much of that resonance turns into power. If you want to use the Guitar-Amp analogy from the manga, Clare's an amp limited to going to 2 instead of all the way to 11 10. The first part is Clare's distrust in others, she's been hurt by both her parents, her sister (through absence), three ex-boyfriends (one currently her step-brother), and two ex-best friends. Some of these hurt more than others (her family, one of the best friends) due to the trust lost is the trust worked on the most. Protecting herself from being hurt again, Clare doesn't want to present a weakness to people she isn't already okay with.

And in the other hand Clare can't help but notice that in all of these failed trust situations, the only common denominator is her. Her best friend betrayed her, her boyfriend cheated on her, her sister abandoned her, her parents lost focus on her. Maybe she's too selfish, maybe something about her is wrong, all these people seem (from her perspective) capable of being something with others. Capable of trust, and respect, just not with her in the mix. Everyone she's ever put care into has turned on her, maybe she just isn't meant to have friends, a boyfriend, happiness. This thought process makes Clare doubt her own connection to others, also limiting her spiritual connection when resonating.

Which is why Madness Clare (who lost her fear, and a great deal of her issues along with) was able to quickly match wavelengths with people and had a stronger ability set while resonating with both her partners during the event. While Mad Clare was more self-indulgent, she was still overall a good person. So her desire to please others did please her still, letting her wavelength seamlessly match Neji or Eve (even when she was less mad during the rescue). And her confidence (She's hot, she's a good person, why shouldn't everyone love me) and trust (well, these aren't those losers I knew at home) issues faded away, letting he hit stronger resonance than she could ever manage as she is.

She also didn't feel guilt about her emotions, which is a dampener on Clare's secondary weapon powers. Clare equates much of her emotional range with sins, specifically the ones she needs to access her only offensive power (anger = wrath). Likewise she has no sin attached to her stealth powers, as she could nearly call it a virtue (to be below sight is to be humble). Without that limiter she could access the Rose Shield (she had every right to be angry at the Kishin, the zombies, the familiars, and the witches), but lost her ability to use her Wallflower Shield (she is smart, sexy, fun, nice, why the hell would anyone want to hide that away?)

See a Teal Deer in all that? Overall it means Clare needs about five minutes to a half hour to match wavelengths with a new partner, but eight months of couples counseling to get anywhere near thinking about a Resonance Strike. ...Issues her partner has not withstanding, as those could extend either number.