Realis Phantasia

Realis Phantasia, also known as the Divine Eye that Sees Through Fantasy and Reality, is a powerful and unstable Sacred Gear that is a candidate to becoming a Longinus. It has the ability to rewrite that of reality and turn it into fantasy and fantasy into reality through the use of the wielder's imagination, though it only affects things that they see. It comes with many downsides, however, which is why it is usually unstable. The only known wielder at this time, is Chika, a human/Dragon Hybrid.

Summary
An incredibly powerful Sacred Gear that is incredibly difficult for normal wielders to actually use, due to the strain it puts on the body. Members of the supernatural world, such as Devils, Angels, and Dragons, could potentially use the Sacred Gear to a much higher level than that of any human - as most humans usually die from losing control of the Sacred Gear or from burning away their lifespan.

It is a candidate to become a Longinus, though it will only become one if a wielder appears that can properly use the Sacred Gear and manages to achieve Balance Breaker. It is believed to be at the level of a Mid-tier to High-tier Longinus if Balance Breaker is ever achieved.

It is believed to be the "Eye of Christ", however this is most likely false.

Appearance
Realis Phantasia takes the form of either the left or right eye in the body of the wielder, which in turn, causes the eye's sclera to blacken and the iris to become blood red, with the pupil becoming shaped like a cats' eye.

Abilities
Realis Phantasia possesses the ability to rewrite that which is reality, making it into fantasy, and vice versa, through the use of the user's vision (of the Sacred Gear) and from their imagination. It is a form of "subjective reality" which allows the user to manipulate the boundary of what is fantasy and what is reality, in other words, what is and what isn't, and to rewrite the reality as being fantasy and the fantasy as being reality.

For instance, it can cause a ball of flame launched towards the wielder, which is the "reality" to become "fantasy", and thus disappear, as if the attack had never commenced in the first place. The other side, is that it can create a ball of flame out of "fantasy" to make it "reality", and thus making it form before the user. However, to do either of these two things, the user must be able to perfectly imagine it happening; if they cannot do so, then it will not come to pass.

Weaknesses
Realis Phantasia possesses many weaknesses, some are not that bad, while others can even lead to the death of the user.

For starters, when the Sacred Gear is awakened, it cannot become deactivated. It will remain in either the left or right eye, until it is plucked out or the wielder dies. When the user is incredibly close to death, to the point that they cannot possibly use the Sacred Gear, or has died, the eye that the Sacred Gear had appeared in will undergo a small change, being that the iris will turn white and the pupil will disappear, though the sclera will remain black. There has been no exceptions thus far, but it does not mean that it cannot happen. It is unknown if the Sacred Gear can be switched off, but so far, there has been no evidence (besides from looking towards other Sacred Gears) that support this theory. There also exists a strain from the Sacred Gear and this cannot be avoided, even if the eye is covered. The user will always feel the Sacred Gear being active and they will always feel pain because of it - it also means that supernatural beings, such as Devils, can potentially sense the Sacred Gear easier than from any other Sacred Gear users, as it is always activated.

When using the Sacred Gear, the eye that it appears in may start to bleed - however, this is a normal occurence for every wielder of Realis Phantasia. Beyond this, the use of the eye must be kept at a minimum, because if it is overused, then it can cause the user to go out of control due to the power of the eye that they possess, and to inevitably die due to their lifespan being burned away.

To blend fantasy into reality and to burn reality into fantasy takes a lot of power, whether the individual has this power or not is up to debate... but, to do something that will take too much power, means that the difference between the "level of power that the user possesses" and the "level of power that the Sacred Gear must overwrite" must be made up. The difference is taken from the user's own lifespan, which can cause them to die prematurely.

Weak hosts cannot properly control this Sacred Gear, this is simply a fact. It takes a lot of control to make use of the Sacred Gear and oftentimes, the user's greatest enemy is their self, due to their own imagination, which can cause the Sacred Gear to go out of control.

Forms
Because this Sacred Gear is incredibly unstable, and most of its users die a premature death, no Balance Breaker has ever been achieved and recorded. Though, if one was, then it was most likely short-lived.

Trivia

 * The eye is based off of Akame's eye after she used her Trump Card, from Akame ga Kill.
 * The ability is based off of the power of Yukari Yakumo from Touhou.