According to sources that I have followed (sorry, can't recall all of them) is Putin has had a Russian doctor and thyroid cancer specialist follow his entourage everywhere over the past year. In addition, Putin's face appears similar to someone who has been taking large doses of Prednisone ( a corticosteroid ). This drug is also used to treat auto-immune diseases. We call this appearance "Cushing-oid" in reference to Cushing's Disease ( look it up ).
There are reports that he will undergo surgery in the near future for cancer ( type was not specified ) and will hand over control of the government to the architect of the invasion “Viktor Mikhailovich” former FSB aka Nickolai Patrushev (
https://nypost.com/2022/05/02/nikolai-patrushev-could-be-in-charge-of-russia-should-putin-be-sidelined/ ).
Perhaps, Putin seeing that his days are numbered wants to be remembered in Russian "history" as Vladimir the Great, who conquered Ukraine and restored the Russian Empire. In other words, finishing the job he started 23 years ago.