Thor by Donny Cates Vol. 6: Blood of the Fathers

"The gates to Valhalla are broken, and the souls of all who inhabit have vanished! On a quest for answers, Thor must face Doctor Doom in a battle of wits, morals and might! Doom's latest plot lies deep in Asgard's history. And nothing, not even time itself, will stop him from getting what he wants--except for maybe Thor, who must pursue him to protect reality! On a race through time, Thor and Doom find Thanos at the heart of it all--finally revealing the power struggle that brought Thor's grandfather, Bor, to all-out war with the Mad Titan! The ultimate weapon has been hidden away for millennia, but Doom will stop at nothing to control it! Plus, Thor teams up with Black Panther to repay a debt to a god! Collecting Thor (2020) #31-35."--Publisher description.