Phenomena Intervention, also known as Observation is an ability that is used by various characters and major plot device in BlazBlue series. An ability called Power of God, in the most basic terms, it is an ability to change whatever event a user by picking different outcomes from infinite possibilities, changing reality completely.
Phenomena Intervention is a power of Azure, and without it the uses of this power are extremely limited. Hence, some users actively seek to gain the Azure like Takamagahara System. That being said, the limited version of Phenomena Intervention is still fairly powerful.
Here are the abilities/uses a person can achieve by acquiring this ability:
- Existence Erasure: One of the main mechanics of the Phenomena Intervention is to erase a phenomenon and replacing it with a new, meaning a user can automatically erase phenomenons the moment he/she acquired the ability. By not observing a person, they can also erase a being from existence due to being not recognized.
- Subjective Reality: Phenomena Intervention is able to change the world around the user depending on what they "see" and "observe".
- Time Manipulation: Clavis, with one of the weakest abilities to observe a phenomenon, was able to interfere with the time itself. This includes stopping it entirely, as seen when he was talking with Naoto.
- BFR: An average user like Nine was able to send the majority of characters to another hierarchical city in Central Fiction, though with the help of Requiem. Kokonoe managed to send Hakumen to somewhere else with it as well.
- Causality Manipulation: Kokonoe, who is said to be weak when it comes to phenomena intervention, was able to create causal pathways to salvage Hakumen from Boundary.
- Limited Non-Physical Interaction: Phenomena Intervention makes nonexistent beings temporarily exist, as seen when Amane observed Ragna that was already erased by Amaterasu.
- Resurrection/Psuedo-Regeneration (Mid-Godly) and Immortality (Type 3, 4 and 5): Self-observation allows users like Terumi to appear back to existence after Hakumen erased him across the timeline. Observers can't die by conventional means.
- Conceptual Manipulation (Type 2 and 3): With self-observation, user can separate parts of themselves as seen with Noel observing herself to separate Mu from her body. This is seen when Amaterasu manipulated the concept of "world" coming from already erased universe.
- Quantum Manipulation: With Phenomena Intervention, a user like Kokonoe is able to manipulate quantum superposition, and phenomena intervention is similar to Schrodinger's cat experiment.
- Power Nullification: Amane was able to suppress Black Beast by observing Ragna.
- Pocket Reality Manipulation: Rachel was stated to be able to create a pocket dimension with her phenomena intervention.
- Paralysis Inducement: Nine was able to paralyse Ragna for a period of time while using phenomena intervention.
- Probability Manipulation: Phenomena Intervention's main mechanics is to manipulate possibilities to interfere with phenomena.
- Memory Manipulation: Stated by Es that phenomena intervention can easily erase memories used by Takamagahara System to erase people's memories.
- Empathic Manipulation: By Amaterasu's observation, nobody in the world neither hate nor fear Terumi anymore and was able to erase every single hate in the world to Terumi except one in Chronophantasma.
- Law Manipulation: Nobody was able to create her own rules within her own pocket dimension like someone needs to solve a riddle to enter the deeper floor.
- Reality Warping: Phenomena Intervention can make anything a reality as long as it has the smallest of possible chance.
- Information Manipulation: Embryo can manipulate information down to personal level with its phenomena intervention.
- Data Manipulation: With powerful enough phenomena intervention, the user can rewrite even data, as seen when Amaterasu rewrote Kokonoe's backup data.
- Sealing: This is seen when Amaterasu manipulated the concept of "world" coming from already erased universe to create a prison for Embryo.
- Fate Manipulation: Killing anyone outside of phenomena intervention is killing outside of fate itself. Amaterasu manipulated destiny of the Dark War, creating coincidences that are too good to actually come true normally, such as Mind inventing Ars Magus with less than a year in the heat of the war.
- Mind Manipulation: T-System should be used to manipulate the minds of entire humanity to its will using phenomena intervention when it has Hinata.
- Precognition: T-System should be used to precog the events of entire humanity using phenomena intervention when it has Hinata.
- Possession: Raquel was able to possess Rachel with it.
- Spatial Manipulation: Amaterasu was able to warp space according to Chosen's perspective. With Azure, phenomena intervention is able to affect the space-time as a whole.
- Duplication: Hinata was able to create completely new Toya using her own memories.
- Creation: With this phenomenon intervention, the user can create timelines with ease as seen with Hinata.
- Information Analysis: Raquel was able to scan every piece of information within the Boundary, every moment in every event in every possibility.
- Illusion Creation and Power Mimicry: Amaterasu was able to create illusions that have every single ability of the people it copies.
- Telepathy: Raquel was able to telepathically talk with Izanami and Naoto by directly observing Embryo.
- Body Puppetry: Raquel was able to stop Naoto's hand from touching Azure. Raquel was able to forcefully keep Naoto's body in the universe.
- Soul Manipulation: By observing Arakune, Kokonoe was able to give Roy's soul free spot in the Boundary by manipulating him indirectly.
- Time Travel: Noel and Izanami were able to send Ragna back in time, and thus, logically can do it to themselves by self-observation, in fact, it may be already done to Mu by Noel.
Type 1: Small Scale
This level of intervention is, as the name suggest, used for small scale events. Such an example includes a theoretical scenario of changing Ragna's fate of falling off a cliff, or during Calamity Trigger where Kokonoe uses Phenomena Intervention to warp Hakumen out of the cauldron while he rested there for nearly a century to name a few.
Type 2: Large Scale
This level of intervention is used for large scale interventions, such interventions include creating entire timeloops, or distorting all of reality like when Noel caused the Continuum Shift to name a few.
- In some usage, most times when used in wide scale, needs seithr in order to do so, though this is barely exploitable as this kind of observation is barely used in combat, or it won't be used at all.
- In order to affect someone with phenomena intervention, one must need to be able to be observed. This doesn't mean you can avoid it's effects by being invisible, however. One must need to have specific ability or equipment to be invisible for Observers, such as Izayoi or power of Chronophantasma.
- Observation is, to some users, extremely tiring and takes a lot of energy. It is also the reason why some use of PI needs extreme amount of seithr to do so. This is evident in Kokonoe's case, when her observing two people is enough to tire her out. This is also especially true with self-observation, as shown with Terumi in Wheel of Fortune CD, when he is puking because of the toll of the constant use of self-observation.
- Self-observation, a type of observation when a user observe her/himself, is temporary, at least to normal users. This is evident with Terumi's case, when his appearance into the world during Ragna's childhood were temporary and only had weeks at least during Central Fiction.
- Observation, while it is a powerful ability, can't make something that is virtually impossible to a reality. This is stated during the conversation of Naoto and Raquel, when she stated that Phenomena Intervention can't make something impossible possible, which is evident with how Phenomena Intervention works.
- Observation is sometimes uncontrollable even by the user. Es and Nobody, even with their mastery of Phenomena Intervention, cannot stop the Embryo from passively altering reality with Phenomena Intervention. This is also true when the user has some sort of mental instability or has extreme emotional conditions. This is shown when Noel was subconsciously started Continuum Shift against her will, due to the panic and anger she is feeling alongside various mental abuse she took from Terumi.
- Users of self-observation doesn't automatically make them observers. The most popular example if this is Black Beast and Nox Nyctores, former being Anti-Observer Armament due to constantly observing itself and the latter constantly observing itself to keep its power strong or growing.
- Some usage of Phenomena Intervention can't be used properly by some users, or at least can't be used on scale that it can be usable in terms of battle. This is evident with Clavis when he can use Observation to stop time but isn't strong enough to warp reality.