The most source-supported strategy is to solo King of Thunder/Arcapex with a Guardian suit, a sacrificial filler, Lava Rock for percent-HP damage, and a defensive Terrigon that sustains through the boss’s heavy hits.
Evomon‘s final boss is a brutal damage sponge, and the only consistently reproduced clear is a solo run that out-sustains it rather than out-damaging it. The plan leans on one steady source of chip damage and one near-unkillable healer, with everything else built around surviving a periodic ultimate that ends the run the moment you’re caught low. You don’t burst this boss down — you bleed it out while staying healthy.
The build that clears King of Thunder
King of Thunder is the name most players attach to this encounter, though the in-game label is reported as Arcapex, and you’ll also see it written Arcapex. It’s worth flagging up front that the name isn’t fully settled — one account holds that no Evomon boss is verifiably called “King of Thunder” at all, so treat the title as the topic, not a confirmed in-game string.
Loadout to bring before the fight
| Slot | Recommended pick | Purpose | Source-supported note |
|---|---|---|---|
| Suit | Guardian suit | Cuts boss damage by 11% | Stacks with Terrigon’s defensive trait for survival. |
| Damage | Lava Rock (evolves from Levite) | Ultimate deals percent-HP damage every turn | Found on Lava Crag Island. |
| Sustain | Terrigon (evolves from Tarot) | Seed Bomb stacks to 10, heals up to 80% max HP/turn | Found on Murkwood Island; needs a defensive trait. |
| Trait | Stoneheart (or similar defensive trait) | Survive heavy hits and the boss ultimate | Used on Terrigon in the reproduced clear. |
| Filler | Any throwaway Evomon (e.g. Bublade) | Faints first for a free Lava Rock switch-in | Meant to be sacrificed at the start. |
This is a two-Evomon plan with a third throwaway up front. The Guardian suit shaves 11% off the boss’s hits, which matters because every point of mitigation helps you stay over the HP line its ultimate punishes. Your real win condition is Lava Rock — the evolution of Levite, found on Lava Crag Island — whose ultimate ticks a percentage of the boss’s health every turn. Sustain comes from Terrigon, the evolution of Tarot from Murkwood Island, and it absolutely needs a defensive trait like Stoneheart to survive long enough to heal.
How to solo King of Thunder in Evomon
STEP 1/5
Lead with a throwaway Evomon
Send out a filler such as Bublade and let it absorb the opening hits so it faints quickly.
STEP 2/5
Switch Lava Rock in and use its ultimate
On the free swap after the filler dies, bring Lava Rock in and fire its ult so the boss starts taking damage every turn.
STEP 3/5
Let the percent-HP damage tick
Lava Rock’s ult chips a percentage of the boss’s HP each turn, and that slow burn is your entire win condition.
STEP 4/5
Bring in Terrigon and stack Seed Bomb
Switch to Terrigon and spam Seed Bomb up to 10 stacks to heal as much as 80% of max HP per turn.
STEP 5/5
Hold above 70% HP and play around the ultimate
The boss unleashes a big hit roughly every third attack that can one-shot you below 70% HP, so top off before it lands.
Never sit below 70% HP heading into the boss’s roughly-every-third-attack ultimate — with a defensive trait and Seed Bomb stacks ready, that single habit is what keeps a long stall from ending in one hit.
Video help
Boss mechanics that shape the strategy
| Mechanic | What it means | How to respond |
|---|---|---|
| Very high HP | Reportedly around 4,100 HP (unverified) | Win with percent-HP damage over time, not burst. |
| High level | Said to be max level 200 | Expect heavy hits; stack all the damage reduction you can. |
| Status immunity | Immune to burn, poison, frostbite and other statuses | Skip damage-over-time status; lean on Lava Rock’s percent-HP ult. |
| Stat-drop refresh | Clears stat reductions you apply | Don’t build around lowering its stats — they won’t stick. |
| Ultimate every ~3rd attack | A big hit that can one-shot below 70% HP | Top off with Terrigon and a defensive trait before it fires. |
Every part of this loadout exists to answer something the boss does. It’s a massive sponge — a single showcase run puts it at roughly 4,100 HP and level 200, though those exact figures aren’t independently confirmed and should be read as ballpark, not gospel. Because the pool is that deep, flat damage won’t cut it, which is exactly why Lava Rock’s percent-based ult is the core of the plan.
The nastier wrinkle is that the boss is immune to abnormal status effects — burn, poison, frostbite and the like simply don’t apply — and it even refreshes stat drops, so debuff strategies fall apart. The one attack you genuinely have to respect is its ultimate, which lands about every third attack and can delete you outright if you’re under the HP threshold.
Mistakes that cost you the clear
The most common way to lose is to fight the boss the way you’d fight anything else. Leaning on burn, poison, or frostbite is dead on arrival against a status-immune target, and trying to grind its stats down just feeds the refresh. If your damage isn’t coming from Lava Rock’s percent-HP ult, you don’t really have a plan.
Frequently Asked Questions
Can King of Thunder/Arcapex be beaten solo?
Yes — a single showcase run cleared it solo using a Guardian suit, a sacrificial filler, Lava Rock for percent-HP damage, and a defensive Terrigon for sustain. No team is strictly required with that setup.
Why does Lava Rock work if the boss is immune to status effects?
Because Lava Rock’s ultimate deals percent-HP damage, not a status condition. Burn, poison and frostbite are blocked, but a flat percentage of the boss’s health bypasses that immunity and chips it down every turn.
Which trait should Terrigon use?
A defensive trait such as Stoneheart. Without one, Terrigon takes too much damage to reliably stack Seed Bomb and heal, and the boss’s ultimate becomes far more likely to one-shot you.
Does burn, poison, or frostbite work on the final boss?
No. The boss is immune to abnormal status effects, so damage-over-time conditions do nothing and shouldn’t be part of your plan.
Are Thunder Cliffs, Marigon evolution, and Stellar Sentinel confirmed for this strategy?
Not for this clear. Those come from wider community claims and aren’t confirmed by the reproducible Lava Rock/Terrigon run, so treat them as unverified rather than required steps.
