Tikal in The Diamond Series
Tikal appears in...
SatAM Goes BOOM!
Diamond in the Sky
Infinite Sadness
Ghost in the Maze
Diamond Canon...
Tikal is a gate-keeping spirit/ghost. Chaos energy gives her this power, she shares Chaos' ability to open other realms.
She is friends with Shadow due to his ability to connect with multiple versions of himself in other dimensions. In SatAM Goes BOOM!, Tikal uses her powers to transport Boom Sonic and Modern Shadow to Mobius. In Infinite Sadness, it is revealed that she used her powers to transport Shadow into the Boom Universe, while he was falling into the Earth's atmosphere at the end of SA2, making Boom Shadow the original Fallen Shadow. In Diamond in the Sky, she reluctantly allows Rouge to reenter a portal to recover Silver 2.0.
Tikal in the Ghost in the Maze
In the story, Ghost in the Maze, when Chaos becomes Infinite Chaos, Chaos chooses to restore Tikal's body. When Tikal's ghost-self disappears, she becomes light-particles that remain in Null Space. When the Damn Fourth Chaos Emerald enters Null Space, the Sol Emeralds (which are also in Null Space at the same time) must be deposited into another realm, since the Sol Emeralds cannot exist in the same realm as the Chaos Emeralds. Infinite Chaos chooses Seaside Island as the location to deposit the Sol Emeralds... and Blaze, who is also trapped in Null Space via Solaris' doing (Blaze is the guardian of the Sol Emeralds).
Infinite Chaos' reasoning for choosing Seaside Island is that, this is where Tikal wants to be... with Zero. Chaos regenerates the body Tikal gave to Chaos thousands of years ago, so she can have a second chance to live the life she wanted back then, with her best friend, Anubis (Infinite reincarnated).
Tikal is freed from the curse of the Echidna Tribe and can be with Zero, because Zero and Tikal represent (to Infinite Chaos/Chaos' new person merged with Anubis' powers) the kind of love and unity that could have stopped the war between Chaos and the Echidna Tribe.
In other words - Infinite Chaos is pleased with Anubis and Tikal and their love that defeated evil Solaris. Chaos blesses them with a new life together. As a side effect, this also blesses Silver and Blaze with a second chance to be together.
