Contrary to the "black legend" of monolithic Spanish cruelty, King Charles V and contemporary Spanish chroniclers condemned the killing of Atahualpa. They viewed it as an "infamous disservice to God" and an "outstanding evil," not a justified act of conquest.
Despite commanding armies of tens of thousands, Inca generals were so disoriented by the unheard-of capture of their divine emperor that they offered no resistance. This complete bewilderment allowed a handful of Spaniards to dictate terms to a vastly superior force.
To provide legal cover for killing Atahualpa, Pizarro held a rudimentary trial. The emperor was charged with a mix of political and religious crimes like regicide and incest, demonstrating the Spaniards' deep-seated need to frame their actions within a legalistic framework for their king.
Atahualpa prioritized defeating his brother Huascar over addressing the existential threat of the Spanish. He viewed the conquistadors as a temporary factor to be managed, not a permanent invading force, a miscalculation that cost him his empire and his life.
The absolute divine authority of the Sapa Inca meant that capturing a single man, Atahualpa, effectively paralyzed a 12-million-person empire. With no alternative power structure, his generals were bewildered and leaderless, allowing a tiny Spanish force to maintain control.
The arrival of a new Spanish faction under Diego Almagro created a power struggle. Almagro's men, who had no relationship with Atahualpa and wanted to seize Cusco's gold for themselves, successfully pressured a reluctant Pizarro to kill the emperor to advance their own agenda.
The threat of being burned was horrifying to Atahualpa because Inca belief required the body's preservation for the afterlife. He accepted Christian baptism at the last moment only to be garroted instead, a strategic choice to ensure his body remained intact for his own religion's paradise.
In a ruthless political move, Atahualpa directed the gold-hungry Spanish to loot two of the empire's most sacred temples. Both were located in regions loyal to his civil war rival, Huascar, effectively using the invaders as a tool to punish his internal enemies.