Regeneration crisis
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Regeneration crisis was a possible symptom of regeneration.
After having some of his regeneration energy siphoned into a newly regenerated future incarnation, who he had learnt had fallen asleep, the Third Doctor suggested that he was suffering from a regeneration crisis. (PROSE: The Christmas Inversion [+]Loading...["The Christmas Inversion (short story)"])
Following the Fourth Doctor's regeneration, the Tremas Master made a failed attempt to defeat the Fifth Doctor during his regeneration crisis. (PROSE: The Quantum Archangel [+]Loading...["The Quantum Archangel (novel)"], TV: Castrovalva [+]Loading...["Castrovalva (TV story)"])