What it does
Electromorphosis gives the holder a 'charged' state whenever it takes a hit from an attack. While charged, the next Electric-type move the holder uses gets ×2.0 power — identical to the effect of the move Charge. That charged state then gets consumed when you fire the Electric move.
In damage terms: a 100-base-power Electric move under Electromorphosis charge hits at effective power 200. With Bellibolt's 127 Special Attack, that's a hit that can catch physically-defensive Pokémon off guard — a Thunderbolt that would normally leave something at 40% HP might KO under this.
Any attack triggers the charge, including special moves. You don't need physical contact. If you get hit multiple times in a turn (multi-hit moves), the charge resets each hit but still caps at one charge stack — no stacking to ×4.
The charge carries over between turns. You don't have to use your Electric move immediately — it'll still be powered up next turn.
Who runs it
Bellibolt is the only user (98%). Water/Electric typing, 127 Special Attack, and 109 HP give it the bulk to absorb hits repeatedly. Speed is 55, which puts it firmly in 'takes turns before hitting back' territory — that's fine, because taking hits is literally how the ability builds power.
Typical moves: Thunderbolt or Thunder for the main Electric threat, Surf or Scald for Water coverage (no charge benefit, but important coverage), Chilling Water for Attack drops, and Protect to stall dangerous turns.
How to use it
The loop: take a hit → get charged → use a high-power Electric move next turn while the opponent has to respond to the threat of that doubled-power attack.
This puts the opponent in a dilemma: don't hit Bellibolt, and it keeps using normal-power Electric moves. Hit it, and it charges up for a much stronger hit next turn. That dynamic makes Bellibolt more threatening on the field than its raw stats suggest.
In doubles, Bellibolt pairs well with Electric Surge setters — Electric Terrain adds 1.3× to Electric moves, stacked on top of the 2.0× charge. Under rain, Thunder has 100% accuracy, adding even more output. The combination is significant.
Protect doesn't trigger the charge (you need to actually take damage). Plan around this: turns you Protect are turns you don't charge.
Tips & strategy
Don't waste the charge on a hit that won't achieve something — a 2.0× Electric move that still doesn't KO or cripple the target is a missed opportunity. Save it for the turn where it secures a KO.
Experienced opponents who know Electromorphosis may avoid hitting Bellibolt directly — using status moves, switching, or targeting its partner instead. When that happens, Bellibolt plays more like a normal attacker without passive charge-building.
Avoid Choice Specs with Electromorphosis if you can help it — locking into one move risks using a non-Electric move after charging and wasting the bonus. Assault Vest boosts special bulk so Bellibolt survives more hits and charges more often. Leftovers keeps HP up for longer games.