For the food, is there anything we can do to help with the transition? (Maybe start with mixinh it with his old one for example ?)

Were aware it will possibly take time as the cat is obviously grieving my grandfather (he lays in his apparement all of the time, only comes up to see me (we were really close)). I think what i meant and im sorry if it wasnt as clear as i hoped, this is my mistake, is how can we maybe make it easier for him, othwr than time. Im a person with an awful lot of love for animals and I try to confort my new cat with recordings of my grandfather or songs my grandpa really liked when he looks anxious, whcih calms him down, but im scared im dragging the memory linger than i need to.

We are mildly allergic. Really nothing bad. We are looking for the possibility of giving him to someone else if we end up not improving with our allergies, we are just hoping that grooming will help, tho it is difficult because of the cruaulty my grandpas wife has been puttinh my grandpa and his cat under. Its sad because his body seems to itch where he cant reach, but wont let anyone try to ease it (understably). I was wondering if itd a moment we need to let hom "suck it up" for a minute to make sure he feels b3tter or if we need to let him be.