Going for the Harbinger of Doom Dark Ops can feel like a trap at first, because “100 kills in one scorestreak” sounds easy until you watch every streak run out at 40 or 60. If you want a clean setup run (or just somewhere to test your timings), stuff like CoD BO7 Bot Lobby can help you get your hands steady, then you can take the same rhythm into real rounds where the card actually counts.

1) Pick the right moment

Don’t try to force it early. The map just isn’t dense enough and you’ll waste the streak. Aim for Round 20 as a baseline, but if you can comfortably push a bit higher, do it. More bodies on the map means less dead time between spawns, and that’s what kills most attempts.

2) Turn the map into a factory

Flip on Rampage Inducer when you’re ready to commit. Yeah, it gets messy fast. That’s the point. You’re not playing “safe” here, you’re playing “fast,” because you need zombies replacing zombies while your scorestreak is still active.

3) Use ARC-XD for the actual clear

People always reach for the biggest streak and then wonder why it fizzles. The ARC-XD is the sneaky pick because it keeps working while you move it, and it can rake kills without you having to aim a gun. You’re basically turning the round into a moving blender.

4) Fix the armor problem with Kill Joy

Later rounds love throwing in armored stuff that soaks damage and steals your time. Pop Kill Joy right before you deploy. That Insta-Kill window is everything. It turns the ARC-XD’s pulses from “chip damage” into instant deletes, even when the game’s trying to slow you down.

5) Train first, then drive slow

Spend a minute training. Big, tight, ugly pile. Don’t get impatient and thin it out. Once it’s stacked, chew the gum and immediately send out the ARC-XD. Here’s the part most players mess up: don’t rush the detonation. Crawl the car into the edge of the horde and let the pulses farm kills while the next wave is already sprinting in behind them.

6) Detonate only when the pile reforms

You’ll feel it when the crowd thickens again, like the train “snaps” back together. That’s your boom moment. The pulses plus the blast usually push you over the line if you didn’t panic-drive. If you want to practice that pacing without burning real attempts, running CoD BO7 Bot Lobbies for sale style reps can make the timing second nature before you go for the legit unlock.