COMMANDER O'NEIL

Phase Strategy

Commander O'Neil stands alone in the center of the Swamp of Aeonia — until you aggro him. Then he whistles, and four rotted soldiers rise from the scarlet muck around him. This is the fight's entire mechanical hook: kill the adds immediately, or they will kill you while O'Neil blocks your approach.

The arena is a shallow swamp that inflicts Scarlet Rot buildup passively. Standing still for more than 10 seconds will proc rot. The fight becomes a three-way pressure test: manage rot buildup, manage the adds, and survive O'Neil's halberd strikes. Most deaths happen because players ignore one of these three.

Critical: Equip the Immunizing Horn Charm talisman before entering the swamp. It cuts rot buildup by 40%, giving you enough time to kill the adds before your first Preserving Bolus.

Opening — The Summon Phase

O'Neil opens with a horn blast that summons four rotted soldiers — two with greatshields, two with spears. The greatshield soldiers advance slowly; the spear soldiers throw javelins from range. Do not engage O'Neil until the adds are dead. He has hyper-armor on most attacks and will trade favorably while the soldiers chip you from behind.

The fastest strategy:

1. Sprint to the left or right flank immediately after he summons.
2. Isolate the spear soldiers first — they have low poise and die in 2-3 hits.
3. Kite the greatshield soldiers into grouped attacks, then punish with charged R2s or jump attacks to break their guard.
4. Once all four are dead, O'Neil is a standard halberd-wielder with predictable combos.

If you have a spirit summon, deploy it after O'Neil finishes his horn blast. Your summon will draw the soldiers' aggro while you focus on O'Neil directly. Lone Wolves Ashes or Demi-Human Ashes work best — their multi-target aggro splits the soldiers' attention.

Mid-Fight — O'Neil's Halberd Patterns

Once the adds are dead, O'Neil fights like a slower, heavier version of the Tree Sentinel. His halberd has massive reach but telegraphed windups. The key danger is his spinning slash combo — a four-hit chain that tracks aggressively and ends with a wide horizontal sweep.

His patterns:

• Overhead slam — Roll forward into him as the halberd descends. Punish with 2 R1s.
• Spinning slash combo — Four horizontal swings in rapid succession. Roll backward on swings 1-3, then forward through the final sweep.
• Thrust lunge — He steps forward and stabs. Roll to either side. His recovery is long — punish with charged R2.
• Horn blast (re-summon) — At 50% HP, he can re-summon two more soldiers. Kill them immediately or reset spacing to handle them before re-engaging O'Neil.

The re-summon at 50% HP is the fight's only true phase shift. If you are low on flasks when it happens, prioritize the adds over damage on O'Neil. Two soldiers hitting you simultaneously while O'Neil pressures from the front will end the fight.

Attacks & Counters

| Attack | Counter | |--------|---------| | Halberd overhead slam | Roll forward under the swing. Punish 2 R1s or 1 charged R2. | | Spinning slash combo (4x) | Roll backward for swings 1-3. Roll forward through the 4th sweep. | | Thrust lunge | Sidestep or roll perpendicular. Long recovery — safe for charged attacks. | | Horn blast summon (50% HP) | Sprint away immediately. Kill the two soldiers before re-engaging O'Neil. | | Greatshield soldier bash | Circle-strafe. Their tracking is poor. Jump attack to break guard. | | Spear soldier javelin throw | Strafe-walk perpendicular. Do not roll — second throw will catch recovery. |

Recommended Loadout

The loadout for O'Neil is less about damage and more about Scarlet Rot mitigation. You will be standing in rot buildup for the entire fight. Without preparation, you will proc rot 3-4 times and burn through all your flasks healing the DOT.

• Talismans:
  • Immunizing Horn Charm +1 or +2 (mandatory — slows rot buildup by 40-90%)
  • Crimson Amber Medallion (HP buffer for rot ticks)
  • Green Turtle Talisman (stamina regen for extended kiting)
  • Dragoncrest Shield Talisman (physical damage reduction for trades with adds)
• Items:
  • Preserving Boluses ×10 (cure Scarlet Rot instantly — buy from Nomadic Merchant in Caelid Highway South)
  • Neutralizing Boluses (backup poison cure if you clip environmental pools)
• Weapon: Any weapon +12 or higher works. Fire or Holy infusions deal bonus damage to the rotted soldiers. Blasphemous Blade trivializes the fight — the weapon art one-shots soldier groups and heals you on kill.
• Spirit Ash: Lone Wolves Ashes +4 or Demi-Human Ashes +3. Multi-target summons split soldier aggro. Do not use single-target tanks like Lhutel or Oleg — they cannot control four adds simultaneously.

If you are struggling with rot management, craft or buy Immune Cure Meat from the Siofra River merchant. It grants temporary rot immunity for 90 seconds — enough time to kill all adds and chunk O'Neil to 50%.

Anti-Cheese Note

O'Neil can be poisoned with Serpent Arrows or Poison Mist, but rot immunity prevents Scarlet Rot buildup on him. Many players waste Rotten Breath trying to proc rot — it does not work. Stick to physical, fire, or holy damage.

If you want to trivialize the fight entirely, summon Millicent — her golden sign appears on the northeast edge of the inner swamp arena. She is an NPC phantom with high DPS and rot immunity. With Millicent tanking, the fight becomes a cleanup simulator.

O'Neil is not mechanically hard. He is a test of preparation. Bring boluses, manage rot, and kill the adds. Everything else is standard halberd dodging.

Lore Context

Commander O'Neil is one of Malenia's lieutenants, left behind in Aeonia after her bloom against Radahn. The soldiers he summons are not spirits — they are his actual rotted troops, still loyal despite their decay. O'Neil himself is slowly succumbing to the rot; his armor is rusted and his movements sluggish compared to his counterpart Commander Niall in Castle Sol.

Defeating O'Neil grants 14,000 runes and the Commander's Standard halberd — a solid strength weapon with the Rallying Standard Ash of War (buffs nearby allies' attack and defense). The halberd scales with Strength and Dexterity and has innate bleed buildup, making it a strong mid-game option for quality builds.

Related Bosses

After O'Neil, the path east leads to the Dragonbarrow region and Greyoll's Dragonbarrow grace. North from the swamp, you can access Redmane Castle and begin the Radahn Festival questline. O'Neil is not required to progress, but his runes and halberd make the detour worthwhile.

If you found O'Neil frustrating, avoid Commander Niall in Mountaintops of the Giants until you are significantly over-leveled. Niall summons two lightning-enchanted knights and fights alongside them — a much harder version of this encounter.