Flux
Flux — The Encounter
The forge-bound automaton whose fists run hot with bound lightning · a boss your table can run with almost no prep. SRD 5.1-compatible.
Who Is Flux
From the workshops of the Forgebound came a labor not of flesh but of will set in iron. The smiths who raised Flux wound its limbs with conduits of captured storm, so that every blow it lands carries a fragment of the lightning sealed within its breast. It was made to break walls and the men who hide behind them; it neither tires nor doubts, and it feels no pain to give it pause. Bound to a single command-word, it stands inert until woken, then advances with the patience of a siege engine and the temper of struck steel. Those who have faced it speak of the smell of scorched air before the first fist falls, and of the way its coils flare brighter the more it is struck, as though it drinks the violence done to it. Destroy the coils, the old artificers warn, or it will only grow hotter.
Run Flux in Sixty Seconds
- Hold its action until at least two PCs are within 15 ft., then Multiattack the front-liner to set up the prone rider on a double hit.
- Open by charging the cluster and slamming both fists into one target; prone bodies eat the next round.
- Kill-priority is the nearest caster or healer Flux can reach in a single 30-ft. move.
- Warn lightning-users off: every bolt that hits Flux is stored by its coils and added to its next punch.
- Three ways to run it: wall-breaking siege engine, bodyguard automaton chained to a master, or one of several iron brutes screening a flagship boss.
Flux
Large construct, unaligned (obeys its binding)
CR 6 · 2,300 XP · GUIDELINEOvercharged Coils. The red conduits looping Flux's frame store volatile charge. The first time each turn Flux takes lightning damage, it instead gains that much temporary excess: its next melee hit before the end of its next turn deals an extra 7 (2d6) lightning damage.
Siege Frame. Flux deals double damage to objects and structures.
Actions
Multiattack. Flux makes two Piston Fist attacks. If both hit the same creature, the target must succeed on a DC 14 Strength saving throw or be knocked prone.
Piston Fist. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 14 (2d8+5) bludgeoning damage plus 7 (2d6) lightning damage.
Discharge Slam (Recharge 5-6). Flux drives both gauntlets into the ground, releasing its stored charge. Each creature within 15 ft. must make a DC 14 Dexterity saving throw, taking 21 (6d6) lightning damage on a failure, or half as much on a success. Creatures that fail are pushed 10 ft. away.
Bonus Actions & Reactions
Grounding Stomp. Reaction When a creature within 5 ft. hits Flux with a melee attack, Flux may slam a fist down; the attacker must succeed on a DC 14 Strength saving throw or be pushed 5 ft. and have its speed halved until the end of its next turn.
A hulking automaton of blue-and-gold riveted plate, its arms ending in oversized hydraulic gauntlets fed by glowing red energy coils that hiss and crackle with bound lightning. It charges forward on heavy legs, fists already humming.
Flux, Bound
Companion · acts on your initiative
Bound · GUIDELINECharge Sink (signature). When an ally within 10 ft. would take lightning damage, Flux may absorb it: the ally takes none and Flux's next Piston Fist deals an extra 7 (2d6) lightning damage.
Actions
Piston Fist. Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 13 (2d8+4) bludgeoning damage.
Reactions
Bulwark Stance. When an adjacent ally is hit, Flux may interpose its frame, reducing the damage by 5 (1d8) as the blow rings off its plate.
Re-keyed to a new command-word, the automaton becomes an immovable iron shield, soaking storm and steel meant for its keeper.
Guideline numbers — formula-tuned and read from the miniature's design, not yet table-proven. Tell us how it ran in the comments.
How It Fights — by Tier
Same creature, scaled threat. The traits never change; only the numbers move.
Open by stomping into the cluster and swinging both fists at one body to knock it prone. Kill-priority: the squishiest caster it can reach in a turn. At this tier run it as a single elite bruiser with a couple of weak servitors, not a boss.
Open by closing distance and Multiattacking the front-liner to set up prone, then save Discharge Slam for when two or more PCs cluster to revive or gang up. Tell lightning-casters NOT to blast it (Overcharged Coils feeds it). Pair Flux with a controller or a ranged threat so the party can't simply kite it.
Run two or three Flux as a battering line in front of a real flagship boss or inside a charged lair. Open with Discharge Slam the moment the party bunches, then Multiattack the heaviest armor to grind it down. It is an anvil, not the hammer; it needs a bigger threat beside it to matter at this tier.
Put Flux on the table
Download the presupported STL and run the fight tonight — the model, and the encounter that comes with it.
Get the STL on MyMiniFactory →Clay Cyanide Companion Rules v1
How a bound creature acts
- A companion acts on its owner's initiative, immediately after the owner.
- It uses the Companion block above — roughly ×0.6 HP and damage, no recharge abilities, and at most one reaction trait.
- It moves freely; it takes its Action only while its owner is conscious.
- At 0 HP a companion is broken, not dead — restored on a long rest unless your table rules otherwise.
Original Clay Cyanide material © Clay Cyanide LLC — explicitly not the non-SRD official sidekick rules.
Questions, Asked at the Table
What CR is Flux?
Flux is built at CR 6 (2,300 XP) in its native Tier 2 band, with Tier 1 and Tier 3 versions provided so you can drop it into a level 1-4 or 11-15 party without rebuilding the block.
Can Flux be a companion or ally?
Yes. Re-keyed to a new command-word it fights as 'Flux, Bound' (AC 16, 76 HP), a frontline bodyguard that soaks lightning meant for allies and rings blows off its plate with Bulwark Stance.
How do I stop it punishing my lightning damage?
Overcharged Coils only triggers off lightning, so switch to fire, force, radiant, or plain weapon damage. Targeting the red coils with called shots (DM's discretion) or simply outpacing its 30-ft. speed are the other clean answers.
Tell Us How It Ran
This work includes material taken from the System Reference Document 5.1 ("SRD 5.1") by Wizards of the Coast LLC and available at dnd.wizards.com/resources/systems-reference-document. The SRD 5.1 is licensed under the Creative Commons Attribution 4.0 International License available at creativecommons.org/licenses/by/4.0/legalcode.
Clay Cyanide Miniatures is not affiliated with, endorsed, sponsored, or specifically approved by Wizards of the Coast LLC. This content is compatible with the fifth edition of the world's most popular fantasy roleplaying game. Companion rules, lore, names, and original mechanics © Clay Cyanide LLC.
Technical Specifications
32mm, 75mm
STL, Pre-supported STL
Standard or ABS-like resin, 0.05mm layer height
Yes — ready to print, optimized supports included
Played Flux at your table? Log in with your Obsidian Tavern account to leave a balance note, a war story, or a file issue — the sharpest reports get the block revised.
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