Tenkai emerges as an enigmatic monk serving Hideaki Kobayakawa, his demeanor cryptic and actions laced with manipulation. Concealed beneath this facade lies Mitsuhide Akechi, a disgraced Oda clan vassal who staged his demise after betraying Nobunaga Oda. Revelations of his survival unfold through media such as *Sengoku Basara 3 Utage*, where his alternate Mitsuhide-themed costume and narrative subterfuge confirm his true identity.

A shadow orchestrator, Tenkai steers Kobayakawa’s wavering resolve with calculated rhetoric, fueling conflicts to resurrect Nobunaga—an obsession rooted in their fractured past. This vendetta drives him to manipulate Oichi, luring her to Honnoji with promises of Nobunaga’s revival, only to face lethal retribution from the reborn warlord. Tenkai’s cunning ensures survival; he feigns death through staged falls and resurfaces in pivotal clashes like the Siege of Kanegasaki to advance his schemes.

*The Last Party* expands his role as a collaborator with Ōtani Yoshitsugu in destabilizing Japan. He coerces Oichi into inciting massacres, frames Tokugawa Ieyasu to provoke nationwide strife, and engineers Nobunaga’s resurrection through Oichi’s dark magic. The plan collapses when Oichi, swayed by her husband’s spirit, turns against him, delivering the fatal strike.

Tenkai’s duality—a monk’s serenity masking a ruthless tactician—echoes in dialogues hinting at past lives. Allies like Tokugawa Ieyasu pierce his disguise, while his "Evil Eyes" ability mirrors his psychological warfare. Though inspired by the historical Tenkai, a Tokugawa-linked monk, his narrative fixates on cyclical betrayal.

His arc weaves identity and legacy; as Mitsuhide reborn, he discards past failures to chase power, only to unravel when Oichi defies him—a testament to manipulation’s self-destructive toll.