Resonance (Japanese: 共鳴) is a recurrent theme and plot element featured throughout the Beyblade Burst media franchise.
Resonance is a mysterious phenomenon that occurs naturally between a Blader with strong attachments with their Bey (e.g. Valt Aoi and his Valtryek Beyblades). Resonance occurs during moments of intense mental focus and concentration and ignited by a Blader's competitor spirit and willpower. During Resonance events, the Blader radiates waves of power and this power is transmitted to their Bey and harnessed by their avatar for power. The process causes the Bey to emanate the same aura and glow as the Blader and if their Resonance is strong enough, their avatar spirit can manifest entirely during battle.
Resonance is the energy generated through the synchronization of a Blader and their Beyblade's Avatar and is the primary power source for Bladers within the Beyblade Burst canon. This power is measured as Resonance Power (共鳴力)
Though the criteria to acquire this ability is unknown, Resonance responds primarily to intense emotions and it can be assumed that all Bladers possess the ability. Harnessing this energy, a Blader can amplify the power and capabilities of a Beyblade. Resonance-capable characters generate a colored aura which allows them to invoke their Beyblade's avatar.
It is implied that most main characters can use resonance since there are a variety of avatars that has been seen over the course of the series. It is also used in the anime to activate various abilities like the Turbo Awakening and Sparking Shoot. It is likely this has to be trained since it took Hyuga Asahi and Hikaru Asahi a lot of training to be able to do so, but in some cases, like Aiger(who was able to resonate with Achilles since his debut) and Gwyn Reynolds(who could do this with Genesis immediately to use Superior Flux) it is natural.
In Beyblade Burst Turbo, during the battle between Laban Vanot battled Phi in Episode 24, Aiger Akabane started to possess special type of Resonance called the Devil's Resonance (悪魔の共鳴), a corrupted, rage-driven type of Resonance which increasingly influences the Blader's behavior with intense impulses of uncontrollable aggression gained from shared pain. Unlike the usual power generated from mutual Resonance, this type of Resonance dominates the Beyblade's Avatar and is inherently toxic to them. Hyde is another user of this resonance. Both were freed from this when Phi destroyed their Beyblades.
Besides this, Phi and Arthur Peregrine also possess dark resonance since they can turn their beys dark coloured during battle. When Delta Zakuro wielded Venom Diabolos Vanguard Bullet/Erase Diabolos Vanguard Bullet, he may also have used this type of resonance.
- The Avatar is similar to the Bit-Beasts of the Plastic generation.