God of War: Ragnarök gives Kratos a wide variety of combat options, including the use of magic abilities called Runic Attacks. There are two kinds of these abilities: Light and Heavy Runic Attacks. Both of these can significantly aid Kratos in combat. However, the Heavy versions are very powerful and hidden behind side content.
Heavy Runic Attacks do a staggering amount of either damage or stun, or they can apply plenty of elemental effects to the enemies Kratos is fighting. The effects, while powerful have a longer recharge time, though this can be reduced by investing in the Cooldown (CLD) stat. There is a Light and Heavy Runic Attack slot in each of Kratos's weapons. The Light versions of the attacks are fairly easy to acquire, but Heavy Runic Attacks, however, take extra effort to acquire. He can spend experience points (XP) to upgrade the attacks.
Heavy Runic Attacks Can Be Difficult To Find
Unlike the Light Runic abilities, the Heavy Runic Attacks are not given to Kratos as part of the main story quests, and instead are mostly found through side content much later on in the game at around the 15-20 hour mark. These versions of the attacks will further augment the game's weapons. They also require Kratos to explore the Nine Realms thoroughly, found in Legendary chests. These are often off the beaten path as part of Favors, Ragnarök's side quests. Exploration of this side content can help him become more familiar with God Of War Ragnarök's best weapons. This means that he will need to be on the lookout for hidden areas while traversing the game, or undergo Favors given to him by the game's various characters. There are a few exceptions to this rule and can be found in Legendary Chests along main pathways, such as the Atlas Eruption attack for the Blades of Chaos, which can be found in a Legendary Chest along the main path during the main story quest "Forging Destiny".
For example, Ivaldi's Anvil for the Leviathan Axe can be found when Kratos is able to return to Midgard as part of the main storyline quest, "The Path". Getting to this ability requires him to undergo the quest up to the part where he will encounter the first Frost Grodungr. Defeat the beast and the Hel-Walkers that accompany it by using some of Ragnarök's best early runic builds. After the battle, there will be a chain leading upward and then across a small pathway. This will start the "Sigrun's Curse" Favor. The legendary chest containing the ability is found along the path Kratos and his companion will take. This ability deals a great deal of damage and applies frost effects, as well as adding stunning effects when the ability is upgraded. Many of the other Heavy Runic Attacks are found through similar side quests, and it is worthwhile to seek these out at every opportunity and go back to old locations to look around, much like they can for Nornir treasure chests in Midgard.