Very strong emotional ties, behavior in this life is impacted by previous events, usually in shift, personalities & motivations extremely similar:

• Manjiro Sano/Mikey - Tokyo Revengers

Very attached to the source, subconscious similarities:

• Angel Devil - Chainsaw Man

Core, spiritual center, represents the self as a concept or base:

• 9S - Nier Automata

(Note: This list is organized by my experience and memories, not by necessarily the strength of the shift or my attachment. Newer fictional sources are put in the forefront due to my current exploration of them so don't be alarmed that older sources aren't featured. This version of the list feels most relevant.)