Bluestar x Tigerclaw
BlueTiger / TigerBlue
Category: Non-Canon
Bluestar-- Bluestar is a muscular blue-gray she-cat with icy blue eyes and short fur. Her muzzle is tinged with silver and she is lithe, but old.
Tigerclaw-- Tigerstar is a massive dark brown tabby with much darker stripes.
Bluestar, the noble leader of ThunderClan and Tigerclaw, the dark warrior of ThunderClan. Many fans consider the pairing crazy, while other are crazy for it. Tigerclaw in the end of the first series, turned out to be evil, and betrayed Bluestar, his leader. While Bluestar obviously depended heavily on her strongest warrior to help her Clan.
Her devastation to his betrayal, losing her sanity, is what fans of the pairing depend on to support it. Bluestar was shattered when Tigerclaw tried to kill her-- was that the reaction of a broken heart, or just a leader betrayed?
"Subtext" and Evidence
MAY CONTAIN SPOILERS
BluexTiger does not have any canon evidence.
"Bluestar was crouching beside her moss-lined nest. Blood trickled down her forehead, but that did not alarm Fireheart as much as the look in her eyes. They were a vague, cloudy blue, and she stared horror-stuck in front of her as if she was witnessing the destruction of everything she had ever worked for."
Forest Of Secrets, page 276
As always, a subtext can be interpreted two ways. This one is taken from the point of Tigerclaw's betrayal and defeat. Does Bluestar's shock, and line of "everything she had ever worked for" mean ThunderClan, or a romance with Tigerclaw before this turn of events?
"The leader looked at him but did not reply. Fireheart could see that her eyes were still dull and unseeing, as if the discovery of the truth about Tigerstar had bruised her spirit beyond repair."
Forest Of Secrets, page 277
See above point for details.
"Bluestar too looked astonished. 'Fireheart told me his suspicions,' she murmered. Her voice shook. 'I didn't -- I couldn't -- believe him. I trusted Tigerclaw.'
Forest Of Secrets, page 285
She says she trusted him, but does she really mean loved him? And why would she change her statement to "couldn't". Why couldn't she trust the prophecized cat who would save the forest, whose word she never even investigated?
Much similar evidence can be found in the last chapters of Forest Of Secrets.