It's a stunning looking bird, wow! These mottled flight feathers, great! However, I wonder how to exclude a Carrion Crow here? On range alone?
Apart from range (Carrion Crow largely absent from Ireland as a breeding species so perhaps less likely although there are small clusters of breeders and of course ‘vagrant’ occurrence). However, I think in this form of ‘diluted’ plumage, you see the shadow of the normal plumage arrangement of Hooded Crow (plain steely grey mantle, subtle darker feathering on the head/nape) and neat contrast division between the flight feathers and lower back/belly. There is also a contrast in the feather condition imo, the flight feathers showing growth bars from the weaker flight feathers as well as more extensive fading and abrasion. The OP’s flight feathers look also to be leucistic too (as well as ‘pastel’). Partial leucism in crows tends to result patchy black and white plumage or, if a diluted form, with be evenly pale with no organised pattern of coverage if the original colour is black all over, because in diluted (chlorochroism) plumage all the pigments are there but consistently paler (hence the ghost pattern still remaining). Leucistic feathers
sensu stricto are the total absence of pigment, resulting in white feathers and where you get a much more random abberation of white plumage areas.
An excellent paper here
EDIT; I posted the wrong link earlier, I meant to post this one which is better and has some images
(As I noted, this doesn’t need rule out the possibility of hybridity imo somewhere in the lineage since not all hybrids express obvious hybridity in their plumage.)