MGS Delta Hardest Bosses Ranked: Best Strategies for Every Cobra Unit Fight

2026-06-10·Boss Guides

I spent way too long figuring this out and honestly I still feel like there might be an even better way to do it that I just haven't stumbled across yet, but this approach got me through my no-alert run and that's what matters.

I've beaten the Cobra Unit multiple times across the original MGS3 and now the UE5 Delta version, and the difficulty ranking hasn't changed much, but the strategies have, because Delta's New Style controls and AI improvements shift what works. Here's my honest ranking from easiest to hardest, with the tactics that actually worked for me. ## 6. And the Sorrow

This barely counts as a boss fight. And you walk through a river while ghosts float past you. But the ghosts are every enemy you've killed during the campaign. If you played non-lethally, the river is empty and the walk takes 30 seconds. If you killed dozens of guards... it's a long, slow walk while they moan at you. At the end of the river, Snake dies. But you need to use the revival pill (the one The Boss gave you during Virtuous Mission) to come back. If you didn't equip it, you die for real and restart. Check your inventory before this encounter. I forgot on my first NG+ run and paid for it with a 15-minute checkpoint rewind. Difficulty: not a fight. More of an interactive guilt trip. ## 5. The Pain

Hornet controller. Shallow cave pond. He floats, throws hornets, occasionally shoots bees from his mouth (the game doesn't explain this, it just happens). Shotgun to the face when his hornet shield drops. That's the entire strategy. His attack pattern is predictable: hornet shield up, wind up, throw hornets, shield down for about two seconds. Fire during the window. Repeat five or six times. Seriously. The only complication: if hornets land on Snake, they deal chip damage until you roll in the water to wash them off. The pond is shallow enough that you can't drown but deep enough to submerge. Difficulty: tutorial boss energy. If you die here, the later fights will humble you. ## 4. The Fury

Flamethrower cosmonaut in a tight corridor. The arena is the real enemy, narrow halls with debris that ignites and stays burning, limiting your movement space as the fight goes on. Key insight I didn't get until my third attempt: shoot his jetpack. When it sparks and sputters, he's grounded for about eight seconds. That's when you unload. RPG rounds to the grounded Fury end the fight in two cycles. Shotgun takes five or six. Fire camo from the supply room before this fight helps but isn't mandatory. Not kidding. What IS mandatory: equipping burn ointment in your quick-select. Opening the full CURE menu mid-fight while on fire is a death sentence. Difficulty: moderate. More annoying than difficult. The fire damage over time is what kills you, not the direct hits or whatever works.. ## 3. The Fear

Speed is the problem. He's fast, he goes invisible, his crossbow bolts poison you, and the poison blurs your vision while draining stamina. A blurry screen makes it hard to track his movement, which leads to more poison hits, which leads to more blur. It's a death spiral etc.. Thermal goggles are non-negotiable. They reveal his position through the cloak. Without them, you're guessing. My strategy: stand near a tree. When he lands on a branch above you, you'll hear the wood creak. Look up, shotgun blast. It works. He falls, takes ground damage, gets up, repeats. If he throws a flashbang, turn away, the blind duration in Delta is longer than the original and you can't afford it. His stamina pool is small. Non-lethal with the tranq pistol takes about 12-15 headshots. Well worth it for the Spider camo. Difficulty: hard if you don't have thermal goggles. Medium if you do. Easy if you also brought the shotgun. ## 2. The Boss

Yep.

The final fight in the flower field. White petals everywhere. No gimmicks, no adds, no environmental hazards. Just Snake and The Boss trading CQC counters until one of them falls. The fight is entirely about reading her tells. She shifts her stance before charging. She leans slightly before a grapple. The counter window in Delta is maybe 15 frames, tight but learnable. Trust me on this one. If you counter successfully, you get one shot in. One. Then she starts countering again. She adapts. If you spam shotgun shells, she starts dodging. If you keep distance with the sniper, she closes the gap faster. You have to mix up your approach within the fight, not just between attempts. Non-lethal requires landing CQC throws repeatedly without killing her. It's the hardest non-lethal takedown in the game and one of the most satisfying things to pull off. Difficulty: genuinely challenging. The fight demands you engage with the combat system at its highest level. No cheese, no shortcuts. ## 1. The End

A 100-year-old sniper shouldn't be the hardest boss in the game. But he is. The fight takes place across three connected forest maps. He moves between dozens of sniper positions. I learned this the hard way. He has a parrot that spots you from the air and reports your location. He falls asleep sometimes, but if you approach while he's sleeping he might hear you and wake up. You need to track him with the directional microphone, thermal goggles, and by looking for footprints. His scope glint gives him away if you're scanning with binoculars. Capture or tranq his parrot (don't kill it, come on) to remove his spotters. What makes this fight #1: the tension. You can go 10 minutes without seeing or hearing him, then suddenly a tranq dart hits you from 300 meters away and you have no idea where it came from. The fight can take an hour if you're being careful. Sneaking up for a hold-up is the best way to get his camo. You need three hold-ups total. After the third, tranq him for the non-lethal win. Took me forever to figure out. Difficulty: a masterpiece of game design that happens to also be brutal. Game changer, honestly.