Summary
Enchanting is one of the best ways to gain power in Skyrim. With the right enchantments and perks, the Dragonborn can be truly unstoppable. There is a quick way to harvest grand soul gems from sentient NPCs (humans, elves, and beastfolk), but it involves using black soul gems or the Daedric artifact, the Black Star.
Those who know their lore, using black soul gems for enchantments sendthose captured souls to the Soul Cairn to be forever tortured by the Ideal Masters. Not exactly a benevolent act for players looking to role-play a righteous (or just non-evil) character. Thankfully, there are still plenty of power sources available all across the northern province. Just don’t forget to carry a soul trap spell!

1Dragon Priests
Limited In Number
Similar to liches, dragon priests gained their power by submitting themselves to dragons and helping them enslave the Nords of old. Defeating these ancient cursed entities comes with many benefits, including a chest of leveled loot, a destruction staff, a powerful dragon priest mask, and, of course, a grand soul gem.
Dragon Priests can be found in their burial places, usually surrounded by their undead slaves. There are eight in Skyrim and five more in Solstheim, which can be accessed with theDragonbornDLC. Killing and taking the soul of dragon priests vary in difficulty depending on the encounter.Thankfully, a handy list of dragon priests from weak to strong can be consulted here. However, even defeating the weakest of them may present a challenge to lower-level characters.

2Potema’s Remains
Unique Boss Soul, The Wolf Queen Awakened Quest Boss
If the Dragonborn happens to be exploring the caves southwest of Solitude, they may encounter a group of necromancers trying to summon the spirit of Potema Septim, the Wolf Queen, one of Tamriel’s most formidable necromancers. Upon defeating them, they learn that Potema’s spirit actually returned below the Temple of Divines in Solitude.
Defeating and soul-trapping Potema yields a grand soul. Despite being a ghost, she is still technically sentient, and her soul will fit in a regular grand soul gem. However, if the Ideal Masters did happen to claim her soul, it would be a just punishment for all of her years of necromantic evil.

3Draugr Deathlords / Draugr Death Overlords
Level 30+, Hard To Kill
Draugr Deathlords and Death Overlords are the most dangerous Nordic undead encountered in Skyrim. They carry ebony weapons and armor and are tough to beat, even for the most battle-hardened. Enchanters looking to use their souls to power one of their enchantments must come prepared.
Two are guaranteed at Lost Valkygg, which can be found outside the Labyrinthian southeast of Morthal. At least three can be found at Valthume (southwest of Rorikstead), as well as a dragon priest, which also carries a grand soul. Any other Draugr Deathlords will only appear in Draugr ruins after the Dragonborn reaches level 30 and beyond.

4King Olaf One-Eye
Unique Boss Soul, Bard College Quest Boss
The soul of this ghost will fit the empty slot of a grand soul gem and, if nothing else, will make for a memorable top-tier enchantment. Olaf will appear as a Draugr boss in Dead Man’s Respite and can be found by naturallyfollowing the Bard’s College quest lineto the end.
The fight with Olaf is known to be bugged in two ways. While he is supposed to match the player’s level, he often appears as his most powerful leveled version, making it a challenge to crack. However, if the player manages to push him behind his throne, he will become calm and stop attacking, even while the player chips away at his health.

5Falmer Shadowmasters / Warmongers
Level 38+, Hard To Kill
Shadowmasters begin appearing in Dwemer or frozen dungeons once the player character reaches level 38, and Warmongers make an appearance after 48, although both offer grand souls if the player is able to hit them with a soul trap spell first.
They are both formidable melee fightersbut, like all Falmer, are still blind. Magic users would do well to use the muffle spell, which reduces the noise the player’s footsteps make. The boss variants also carry grand souls but are much more difficult to defeat since they come with healing spells.

6Riekling Chargers
Plentiful, Random Chance To Spawn In Riekling Tribes
Rieklings are common throughout Solstheim, found in most caves and ruins and occasionally out in the open. The Rieklings that carry grand souls tend to appear when the player is at higher levels, but the Dragonborn should have reached a decent amount of power before taking the boat to the island anyway.
The highest-level mounted variant of the Riekling is the charger. What makes it especially difficult to take on (and soul-trap) is that,being protective of those they deem worthy of respect, they tend to be surrounded by others in their tribe. Thankfully, the Riekling and their bristleback mount are treated as the same entity and only have to be defeated once for soul capture to take effect.

7Frost Giants
Limited In Number & Hard To Kill
There are only five frost giants in Skyrim (with theDawngardDLC) and one extra-tough boss variant in Solstheim. The five in Skyrim can all conveniently be found in one place, the Forgotten Vale, as part of a quest to obtain Auriel’s Bow. Anyone with enough empty grand soul gems hanging around might want to keep this place in mind (and bring fire spells since they are weak against the flames).
The aforementioned frost giant boss, Karstaag, is one of thestrongest enemies in Skyrim. With 4,000 health points, 100% resistance to frost, and 150% damage resistance, taking this ghostly giant’s soul should count as a legendary feat. Particularly useful is the werewolf transformation, as Karstaag is vulnerable to knockdowns.

8Betty Netches
Hard To Kill, Random Chance To Spawn With Netch Families
These floating jellyfish-like creatures can be found in groups all across Solstheim. They are not dangerous unless provoked. Doing so will cause them to attack the player with powerful electricity attacks. The Betty Netch is the strongest of all and yields a grand soul.
The best advice for those looking to take a Betty Netch soul for enchanting is to use ranged attacks and bring plenty of shock resistance, either through potions or enchantments. Hunters will occasionally be seen trying totake down these fascinating creatures for their leather, which can improve the Dragonbon’s chances. Even at high levels, those without shock resistance will go down fast seconds after landing their attack.

9Ash Spawn Immolators
Limited, Random Chance To Spawn During Ash Spawn Quests
Perhaps unsurprisingly, as the mid-to-upper-level DLC area, Solstheim is home to many grand soul creatures. Ash Spawn Immolators, being higher-level variants of regular ash spawn, are not the easiest soul-prey to find nor the easiest to kill, but they are not the hardest either. They have just under 1,000 health points and a natural resistance to fire damage.
They can be found bursting out of ash pits close to Raven Rock and generally in the southwest of the island. They are associated with a few quests, such as “Clean Sweep” and “March of the Dead” which can both be easily acquired at Raven Rock, although the immolator variants will not likely spawn unless the player is at a fairly high level.

10Mammoths
Plentiful, Multiple Herded By Giants
It might seem logical to assume that giants, being humanoid in form, might have grand souls. Butdespite their formidable prowess in battle, soul-trapping a giant only yields a “greater” soul level. However, their companions and herding animal of choice, the big fuzzy mammoth, do carry grand souls.
Finding mammoths is quite easy, and since there are a lot of them all across the landscape, they are perhaps the best source of grand soul gems in the game. Giant camps are not too hard to find. Defeating a mammoth (and its giant owner) might be a little more difficult. Considering their size and how difficult they find it to fit between small spaces (such as the gaps between rocks and trees), it may be possible to snipe at them from a tight bunker hole.