Naruto: Nine-Tails Mode from the Start

[Transmigration + ruthless and decisive + no saintly behavior + breaks the rules + no female lead + invincible]

While watching Hokage at an internet cafe, Ye Chen unexpectedly transmigrates into Naruto Uzumaki!

He forms an alliance with the Nine-Tails from the start and successfully fuses with the Nine-Tails Chakra!

He lures Kakashi into joining his rebellion, kills Hiruzen Sarutobi and Danzo, combines the three sage arts into one, and seizes secret techniques from every ninja village, women, and Tailed Beasts alike. He strengthens his bloodline, awakens both Pure Eyes, and takes on the Ōtsutsuki Clan.

No female lead