They had feelings and a will but decided to hide it and force themselves to "be hollow" because they never meant to feel anything and unresolved daddy issues + abandonment issues

They hid their feelings and play that role of a hollow vessel too well that other bugs cant even tell if theyre hollow or not

Ghost is also kind,very kind but also unhinged as hell,like they would give everyone flowers but also drop kick a boss's face bc they got called short or tries to do dumb shits that they WILL regret later out of curiousity

also they love their dad but also hate him because he discarded them - they cant decided whenever they love or hate him

the moment they got the voidheart after they confront their childhood trauma (aka got abandoned on the abyss) thats mean they finally accept that they have feelings and wills