Have you ever felt like it was against your character's backstory and alignment (or just plain wrong) to suck the souls from living entities to fuel your weapons and enchantments? What if, instead of souls, you were capturing a creature's magicka on death?

Siphon magicka, not souls

Magicka Siphon is primarily a roleplaying mod.

"Soul Trap" is now "Magicka Siphon," and instead of sucking souls out of the creatures you kill, it is instead siphoning magicka. Magicka gems
are filled, and magicka gems are used in enchantments and to recharge weapons.

Fully voiced! NPCs will naturally refer to magicka gems in dialogue - unless they are really talking about the proscribed black art of using "soul gems" or "soul trap."

Black soul gems are not touched. Now, instead of being basically just a different level of soul gem, black soul gems really take souls - and
thus stand out as the horrific tools of necromancy they are, banned across Tamriel.

So the mod isn't just for good guy PCs, it's also a great addition for an evil character. Now you're Really Evil if you trap black souls! It also serves to add a bit more horror to the too-easy vampire cure scenario.

How it works

No actual mechanics of the game are altered: Rather the strings (text) on spells, effects, items, messages, dialogue, and quest journals are changed (when possible). Every instance of "soul gem" or "soul trap" is changed to instead refer to "magicka gem" or "magicka siphon" where appropriate.

Fully voiced: I've also gone in and replaced all the voiced dialogue in the game that refer to soul gems, primarily using spliced vanilla lines (and a little help where needed from xVASynth).

New gem type: From version 1.1 you can also use Magicka Siphon on NPCs with an "Exquisite Magicka Gem" (uses the Grand mesh with a texture tweak).

For RP purposes, you can still find a rare tome of Soul Trap as well as a Dagger of Soul Trap, in Ilinalta's Deep. (The spell and enchantment are identical to vanilla, if you want to RP a true evil necromancer.)

Replenish your own magicka with gems

But then an obvious question arises: if magicka is the energy that fills these gems, why then aren't we able to simply use these gems ourselves as a magicka source? Well, now you can!

Now you can learn the spells "Drain Gems" and "Fill Gems."

Drain Gems will find a filled magicka gem in your inventory and pull the magicka out of it, filling your magicka reserve and consuming the gem. (Black gems are excluded.) It starts with the smallest filled gem in your inventory, using up one gem per cast. Larger amounts naturally yield more magicka.

Fill Gems does the opposite - fills a gem in your inventory, if you have enough magicka to do so. (Again black soul gems are not included.) Largest gems fill first.

As of version 1.3, Fill Gems now reduces your mana pool by 25 for a set period (1.2 realtime hours, which equals 24 in-game hrs at timescale 20, or 12 hrs at timescale 10). The effect stacks, so filling a lot of gems in a row will drain you significantly for a day or so.

Note that normally, Drain Gems only works with properly-filled gems (no partials, like a Lesser soul in a Grand gem). Used with included YASTM or GIST patches, it will use the smallest 'magicka' (soul) size regardless of gem size it's in. (A petty soul in a Grand gem will be used before a properly filled Lesser gem).

You can buy the spells from Phinis at the College, Nelacar in Winterhold, or Falion in Morthal, and it has a chance of being offered by any court wizard. You can also find tomes in Ilinata's Deep.

Requirements

SKSE

Soft requirement:

Unofficial Skyrim Special Edition Patch: Drain Gems only works on the standard pre-filled gems found in the world, not user-filled gems. USSEP swaps the weird game-generated player gems for the standard world gems (like most soul gem management mods do).

Partially-filled gems will still not be accessible for Drain Gems,  so I recommend pairing the USSEP with Scrambled Bugs with these settings enabled:
- Enable Black Soul Gems (Trap only black souls in black soul gems) to ensure a true division between magicka gems and black soul gems.
- Enable Underfilled Soul Gems (Trap only souls of the appropriate size in soul gems) so all your player-made gems will work with Drain Gems.  

--OR--

Grab a soul gem management mod such as YASTM or GIST to ensure that all your gems are filled to capacity, or to control partially filling gems, splitting amounts into multiple gems, etc. With the patches provided, Drain Gems will work with all of the gems in these mods, even the partially filled ones.

Compatibility and patches

The spells and new Exquisite Gems are added to level lists by script.

Note that no actual gems have been displaced - merely renamed. You will be able to use the 'magicka gems' just like you would 'soul gems' in any crafting recipe or mod quest. (They have the exact same formIDs and that's what the game is really looking for.)

USSEP: I've forwarded its changes without needing it as a master

Scrambled Bugs: You don't need the optional 'Underfilled Soul Gems - Soul Gem Too Small' file, my mod does something similar

Even Better Quest Objectives SE: I've already forwarded the changes in DA01 (Azura's Star) and Hunt and Gather (Wylandria's fetch quest) from EBQO, just load EBQO before my mod. (Patch also provided in case your load order needs you to load it after mine.)

Book Covers Skyrim: Patch for the handful of books I've made text changes to.

Wintersun - Faiths of Skyrim: Patch for DA01 (Azura's Star) quest (also forwards EBQO's changes)

Elemental Staffs SE: Renaming patch for the new staff model

Mods that replace the soul gem model may need patching to retain the reaming of the gems, and/or extend it to the new gems added by these mods.

Use the Synthesis patch for the easiest way to patch your load order for gem replacers.

How-to:


Patches also provided here for:

Recommendations

Your Soul Is Mine - Soul Gem Relinquishment: This is a great addition to Magicka Siphon, highlighting an evil necromancy playthrough even further if you limit its use to only filled black gems (i.e. "real" souls).

Soul Gem Destruction: Gain a small permanent boost to Magicka for destroying filled Soul Gems.

No Black Soul Stealer: Prevents bound weapons with the Soul Stealer perk from trapping black souls (NPCs)

Credits

Early iterations of the Drain Gems spell were based on the work of Crumpmasterjc in Your Soul Is Mine - Soul Gem Relinquishment on their "Absorb Soul" script. Many thanks for their generosity in keeping open permissions on their mod.

BowmoreLover for Lazy Voice Finder - this tool and its integration with Audacity makes splicing a dream.

Dan Ruta for xVASynth 2 - SKVA Synth - when used judiciously it's an absolute gem to find or finish phrasing when splicing vanilla lines.

WilliamImm for Even Better Quest Objectives SE - forwarded its entries for the Wintersun patch

My mods

Diverse Dogs