Renahv might have an aura like a grim reaper with raven wings and a feathered scythe with hidden features

Kingston: can't be sensed
Ruth: alien noises

Briar's aura would be mainly a bright, powerful red color, symbolizing her own desire to make an impact wherever she goes. But also if you look closely, you would notice some faint traces of purple on the edges, almost fading away, as if she were hiding some mystery behind her veil of grandeur.

Hmmm let’s see

Saki: probably a hazy lavender color. Very soft though slightly anxious

Lucia: Probably a shimmery icy blue - very vibrant and energetic. People who sense them can feel her adventurous vibes and would feel invigorated like drinking a good coffee

Creed: warm and robust, and one could feel at ease around his aura. Probably feels and looks like a warm fire on a cold night

Odd: Understated and contemplative on the surface, but dig deeper and you find an overwhelming & cavernous pit of self-aimed negativity (assuming Giratina doesn't feel you poking around and pop up their own aura to scare you away).

Xochitl: Solid and radiant, a reflection of her willpower and passion.

Rosemary: Can keep it pretty hidden all together, but for those who are adept enough to pick up on it; it's a cold, malformed, dead thing, like the visual imprint of an unspeakable thought.

Estella Pre-Incident: Energetic, Contagious, yet not particularly strong.

Estella Post-Incident: The same, but with a raw, primal edge and far more powerful.

Sirius: Same as Estella, but with a touch of melancholy behind it

Gareth: Radiant and warm, yet almost overwhelmingly so. Like goddamn Superman is floating before you.

Shayla: Relaxed and calm, if a bit weak.

Artemis: Tranquil on the surface, but if you look deep a spiraling nightmare looks back at you

Darius: Commanding, dominant, yet a bit sad.

Jasmine: tranquil and refreshing one, like the feeling of taking a nap ant noon on a meadow

Andres: A calm one, that tends to spike or rapidly becomes aggressive when he gets angry

Ace: a Surprisingly Kind one

Avian's looks deminished, like a fire about to go out. You can tell it once roared but now it's almost been snuffed out. Corporate depression and that karoshi lifestyle has hit him hard.

Arryn's is huge and dense, it's like standing next to a tidal wave, there is an overwheming dizzying pressure and it almost feels like you're about to be crushed.

Polly: Surprisingly positive and bright.

Wily:Dark, but very weak, the boy doesn't have a spiritual bone in his body.

Balei’s would be typical blue, maybe some gold bits inside, it’d probably feel like water, very nice and smooth but it can be deadly

Fausto’s is weird, fiery almost, I feel if someone sensed or touched it they would feel like placing your hand directly into lava

Fausto

Summer: her aura is like a massively expansive and tranquil ocean.

Ariella: her aura is incredibly intense. It’s like a radiant, raging fire.

Summer and Ariella are kinda opposite when it comes to aura. Summer has much larger and potent aura, but it’s so calm it’s easy to miss. Meanwhile Ari’’s aura is so intense that it’s vaguely able to be felt by even non-aura users. This is a big part of why Ari can appear so intimidating to others.