Pocket Dimension
Recall Lavos's Temporal Irregularities, presented above in the Observations section for Time. Lavos displays some strange behavior. If the travelers defeat the shell and warp into the past, the shell is still defeated. A strange blue aura surrounds Lavos during the Ocean Palace disaster and the final battle. Lavos Core is able to open time warps to different eras. Lavos also appears to have knowledge of the future; during the final battle it emulate the fighting techniques of Guardian, which exists in 2300 AD. A possible explanation is that Lavos exists within a pocket dimension or "time bubble" which transcends time. When Lavos arrived on earth in 65 million BC, it created a pocket dimension separate from normal space time. A wormhole connects the pocket dimension to every time period. This pocket dimension would exhibit a flow of Time Error; Lavos could access any time period he wished from the wormhole, and would remain constant no matter which era his pocket dimension might be accessed from. Lavos' time axis would be perpendicular to the normal flow of time. Lavos ages within the pocket dimension at a normal rate, but it appears to be the same from any given time period. For example, if Lavos had existed within the pocket dimension for six million years, it would appear to be six million years old from every time period. Anything done to Lavos from one time period, such as defeating the core, would be visible from all other time periods as well. Therefore, if the shell is defeated, Lavos appears to have no shell from each time period.
Lavos is not actually physically present within the earth. The wormhole aperture is located at the earth's core, giving Lavos access to the planet's energy and lifeforms. During the Day of Lavos or the Ocean Palace disaster, the wormhole ascends to the surface, causing a dimensional disturbance. The wormhole offers an uninterrupted view of the pocket dimension, creating the illusion of Lavos' presence. If one approaches Lavos, and passes through the wormhole, the interior of the pocket dimension has appearance of the blue aura which surrounds Lavos. During the Ocean Palace Disaster, Queen Zeal, Magus and the others warp into the pocket dimension. During the final battle, Crono battles Lavos in the pocket dimension. Lavos core is able to open time warps to different times, because it is connected to those eras through the wormhole. The aperture of the wormhole gives a distorted view of the time period being accessed. Lavos is also able to survey the entire timeline and would have knowledge of, for example, Guardian's fighting style. After Lavos dies, the pocket dimension no longer connects to space-time, but the past Lavos exists on a separate timeline.
There is merely one issue with the Pocket Dimension theory -- even if you defeat Lavos's shell in 1999 A.D. before completing the Zeal segment of Chrono Trigger, you can clearly see Lavos's shell intact during his eruption at the Ocean Palace. Additionally, after that segment transpires, if you travel to 1999 A.D. again, Lavos will not have his shell. This renders the 12000 B.C. encounter an anomaly. One possible explanation that works with the game is that the player was not supposed to beat Lavos at the Ocean Palace. This is true because the player must lose to forward the plot of the game.
Another inquiry concerning the Pocket Dimension reads, "if Lavos could observe the eras, why didn't he notice Crono and his crew traveling through time on a mission to defeat him and take action?" The simple answer is that to Crono and the history of the world, Lavos had already erupted in 1999 A.D. at the height of his power. Since Crono and his group most likely confronted Lavos at this time, it would be most convenient for Lavos to simply wait for them and battle at the time of his eruption. Alternatively, if the Black Omen is defeated, the player can seemingly enter the Pocket Dimension from 12000 B.C. The principles behind the PD theory state that it would regardless be at its same power no matter which era it would be accessed from.
