Commander. Full Juggernaut armour, a minigun and an elite guard.

Location: X01 upper floor, around the Main Warehouse. Recommended kit: High-capacity LMG or rifle, plenty of ammunition, Shock Sticks, full armour and spare plates, a Secure Slot free. Possible rewards: Deep Vault Access Key (Legendary, also called Deep Vault 301): opens the Deep Vault gate and Room 301. Helmet sections for the Threat Briefing event: exfil with them, and the whole squad gets credit. Commander rewards; Season 1 payouts not published yet..

1. Clear his elite guard first, from cover, so you are only fighting one heavy target.
2. Keep your distance: his minigun shreds anyone in the open at close range.
3. Use Shock Sticks to stun him, then put sustained fire into him while he is stunned.
4. Squad up if you can; spread out so his minigun can only face one of you at a time.
5. Reload and replate behind solid cover, never in an open corridor.
6. Loot him straight away: put the Deep Vault Access Key in a Secure Slot and grab any helmet sections for the event.

Top tip: His Deep Vault Access Key is not used up when you open the vault. Keep it in a Secure Slot and you can come back for the Deep Vault on later runs.

The Deep Vault is in the north-west corner of the X01 lower floor. Its doors lock behind you and only open for players who also carry the key. X01 boss spots are player-reported and not yet confirmed in game.