Dead by Daylight

to get this achievement you need to need use the Nemesis and His 3 personal Perks, Lethal Pursuer, Hysteria, and Eruption, to use all three in one match you must level it to lvl 10 minimum, I recommend to purposely lose a couple matches (i.e don't kill anybody) to get SBMM in your favor or do it on the 13th of every month were grades and SBMM reset and get SBMM in your favor also equiping addons and offerings will not void the achievement

now with the Patch 6.5.0 update you just need to kill all 4 survivors to get the merciless victory