Showing no mercy is a phrase that describes someone who is unyielding and uncompromising in their actions. The two crossword solutions for this phrase are 'RUTHLESS' and 'BRUTAL'. RUTHLESS is an 8-letter word that means having or showing no pity or compassion for others. BRUTAL is a 6-letter word that means savagely violent or cruel. Both words describe someone who is not merciful and is willing to take extreme measures to get what they want.