"ruthless nature" is correct and usable in written English.
You can use it to describe someone or something that is harsh, unyielding, and lacking in mercy. For example, "The victim of the crime was overwhelmed by the ruthless nature of the perpetrator."
This chapter lays particular emphasis on the ruthless nature of true compassion and the distinction of compassion from love.
But these achievements consistently co-exist with deep personal flaws.Some blunders are explained by the ruthless nature of modern elections.
We are not novices, after all, to the ruthless nature of fundamentalist insurgency, its territorial desperation and, above all, its contempt for humanity.
The fact they are prepared to seize on a decline in their own party's public popularity to hammer home their point underlines the ruthless nature of the enemy May is now facing.
North Korea is another point of tension, with the recent assassination of leader Kim Jong Un's half brother in Malaysia, apparently with a VX nerve agent, a reminder of the regime's ruthless nature.
Questions over her background and faith nonetheless loomed when Haley set her sights on public office in a state long regarded as a microcosm of the ruthless nature of politics.
It's designed not to; a heart-breaking reminder that the beguiling beauty of the hills belie a ruthless, capricious nature.
His case is that the terrorist challenge is global in scope, "evil" in nature, ruthless toward its foes, and eager to control every aspect of life and thought.
The concept of goddesses like Sakhmet and Bast are shaped by its biases, which included a view of women as unpredictable and untamable, and therefore dangerous, and, like the cat, as fundamentally divided in nature: ruthless killer; tender mother.
BBC Sport spoke to some of those who pitted their wits against the Frenchman in his first season in England to find out how he survived the ruthless short-term nature management so often provides.
On September 1, Japan recommenced the ruthless 'War Against Nature' and the dolphins.
