Dead by Daylight

In order to unlock this achievement, you will need to use The Twins' three perks: Hoarder, Oppression, and Coup de Grace. Hoarder will notify you as the Killer when a Survivor interacts with a Chest or picks up an item as well as adds two additional Chests. This can easily backfire since many Survivors run Plunderer's Instinct these days, but also works to be good tracking information if you are not already in a chase. Oppression is an extremely helpful perk as it can cause regression on up to three other generators when you kick a single generator, which helps with the generator defense medal if you can end the game with very few generators done. Lastly, Coup de Grace is a niche perk that can turn the tide of a chase if used properly. This perk gains one charge per generator completed and increases your lunge attack by up to 60%. At pallet loops where a survivor may usually make it, this difference can close the gap and secure a hit. In some cases while using this perk, the extra lunge time it has provided can sometimes negate a Survivor using Dead Hard and will hit them on the later end of the swing anyways if they are still in front of me.

The best way to achieve this in a match is to make sure you are damaging generators (Gatekeeper), chasing and downing survivors quickly (Chaser), hooking all four survivors three times preferably to maximize sacrifice points (Devout), and making good use of Blood Fury and/or the Demon Dash ability (Malicious). Any sufficient combination of these four will increase your emblem score, which in turn will grant you the "Merciless Victory" result you desire. Depending on your rank, you'll need more Iridescent medals. At red ranks, you'll need a clean sweep of four Iridescent medals, whereas other ranks may allow some wiggle room.

In the past, I attempted to do these achievements with just the three perks needed, no offering, no add-ons. For some reason, I think these mess with my outcome, so I just leave them off. However, for these later releases, I've returned to using add-ons and offerings. The only crucial part is that you only equip the three unique perks and leave the fourth slot empty.

At the time of writing, I unlocked this achievement back at the time of the release of this DLC, so please drop a comment below if you are having trouble or need tips with this Killer.