Thor by Donny Cates Vol. 6: Blood Of The Fathers

The gates to Valhalla are broken, and the souls of all who inhabit it 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 maybe for 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 the Black Panther to repay a debt to a god!

Collecting THOR (2020) #31-35.