The MP Gauge is a blue bar that appears over Hero's damage meter, displaying the amount of MP he currently has at his disposal. The maximum amount of MP available is 100. Each of Hero's special moves consumes a certain amount of MP and cannot be cast if the current amount is too low. The amount of depleted MP will appear as a green bar inside the gauge. The gauge will refill as time passes, at the rate of one point every second, or by damaging opponents with regular attacks, with an amount of MP recovered equal to 0.8× the attack's base damage, or damage dealt to shield. Hero can also recover all of his MP instantly through one of the options from the luck-based Hocus Pocus spell. The gauge refilling will be paused if Hero has the Command Selection window open.
If Kirby Inhales Hero he will also gain a fully functional gauge to use with Frizz; unlike other similar meters that can be copied by Kirby, the MP gauge can be refilled and doesn't force Kirby to discard the ability once it's depleted, therefore functioning identically to Hero's own gauge.
Command Selection spells
MP Gain on Hit or Shield (Hero)
Hero will gain MP equal to 0.8× the base damage dealt, or the shield damage. Given shields take 1.19× the damage, Hero will gain more MP for hitting shield. However, no multiplier will affect how much MP is gained outside of this. As such, charged smashes, stale-move negation's freshness multiplier and using Oomph or Psyche Up to increase damage will not affect MP gain. Given critical hits are their own hitboxes, these will increase MP gain. Due to their shield damage reductions, however, they will give less MP on shield.
MP (Magic Points) are a mechanic from the Dragon Quest series. They determine how much mana a character can expend to cast spells. Each spell deducts from this pool at a set rate, and cannot be cast if the amount of MP is too low. MP can generally be restored by using particular healing items, but certain equippable weapons and gear and learnable abilities allow MP to be recovered through alternate methods, such as hitting opponents in battle or regenerating it over time, in a manner similar to how MP replenishes in Smash.
The design of the MP Gauge is based off of its appearance in Dragon Quest XI.