I’m glad you and Santo had so many good years together.
When my husband and I married in 1981, he got a twofer: me and Vixen (aka Vix), a four-year-old cat. Vix lived to be 19 and endured the toddlerhood of our first child before she died. Some cats have an enormous presence. Vix did; her younger companion Max, an otherwise ordinary orange tabby with huge green eyes, did, and so does our current elder statesman, Jinx, a black male, now 17, who we adopted because he was the leftover of his litter and the rescue was giving him away “free” (anyone who has paid vet bills knows there is no such thing as a “free” cat).