Assassin's Creed Valhalla

This achievement requires quite a bit of work. 
 
The first series of upgrades is shown to you and is relatively straightforward. There are five different powers, and you'll first need to find them all before you can upgrade them. You'll find Power of Muspelheim and Power of Rebirth regularly in the beginning of the DLC. Power of the Raven can be found on any of the large black birds around the map. Power of Jotunheim is found at many locations where you actually need to use it to solve puzzles, plus some Jotnar have it. Lastly is Power of Winter, which is found on some Jotnar, but also on a corpse right next to Kara at her arena. You can beginning upgrading each one you find it.
 
For upgrading the powers, you'll need some new resources. The main resource you'll need is silica, which is only obtained from the various raids around the map. There is exactly enough silica to use for all upgrades, plus 6 more for an altar. So you'll need to complete every raid to get all the silica. For the Power of Muspelheim and Power of Rebirth, the other resources you'll need come from killing Muspel enemies. You'll be fighting and killing a huge amount throughout this DLC, so these two upgrades won't be an issue. The Power of Jotunheim and Power of Winter abilities both require resources obtained from killing Jotnar. Initially you won't have much of these, but once you get to the story arc in the southwest region (or if you just explore it to complete the territory) you'll fight many more there and definitely get enough resources to upgrade both of those powers. The fifth power, Power of the Raven, requires giant feathers to upgrade. The only source of these feathers is the giant black birds you'll come across during the DLC (both the live ones that attack you and the corpses with the Power of Raven on them to obtain). This is definitely the only resource you won't come by naturally, and as a result, I highly recommend killing every giant bird you come across in your travels, to make sure you have enough feathers and don't need to grind them out later. 
 
With all the powers fully upgraded, there is one other type of upgrade needed for the Hugr-Rip. The final set of upgrades is only done with Ember. If you work on clearing your map, you may have already participated in a world event with Skavi to track down his crow Kraka on a floating rock. There, you would have obtained your first Ember as part of that world event. You will now need to fly to every single floating rock to get the single Ember on each one. There are a total of 9 floating rocks (and therefore 9 Embers). Two important notes here:
 

• The only way to reach most of them is to not only upgrade the Power of the Raven to extend the duration, but also upgrade the Hugr-Rip to have a second Hugr bar. Then get to the top of the nearest high point, use the Power of the Raven, and hold boost the entire time to fly to the floating rocks. For most, you will need a second usage of the Raven power mid air. NOTE that this second usage must be done BEFORE you run out of the first usage.
• The only way to know which ones you've collected is to zoom in on your map all the way and look at the floating rocks. If there is a yellow dot, ember is there. An X indicates you've already gotten the ember there.

Once you've collected all 9 Embers, you can head to a blacksmith to purchase all four versatility upgrades for the Hugr-Rip. 

In total, you'll need to acquire the following to fully upgrade your Hugr-Rip:
 

• 60 Silica (from raiding Mylna locations)
• 40 Giant Feather (from killing and looting Giant Ravens that can be found around Svartalfheim, they always drop 2)
• 40 Living Spark (from killing and looting Muspels, especially Flame Keepers as they always drop some)
• 40 Magma Blood (from killing and looting Muspels, especially Ash-Bringer and Brann as they always drop some)
• 40 Jotun Seidr (from killing and looting Jotuns, especially Jotnar-Djevelen as they always drop some)
• 40 Frozen Blood (from killing and looting Jotuns, especially Jotnar-Guld as they always drop some)
• 9 Ember of Muspelheim (collected from the Muspelheim Monoliths mentioned in Flying Fortress (10G))

Once you've purchased the two upgrades for all five powers and then all four versatility upgrades, you'll finally unlock this achievement.