Arknights: Guide to OF-EX3 Normal And Challenge Mode

This guide will step through a strategy for clearing OF-EX3 that will work for both the normal and Challenge mode.  

If you are looking for other Event information or Operation clear guides, see the following:

• ALL enemies on this map are weak against physical attacks and resistant to Arts Damage.  Leave the Casters at home for this one.
• The Ergates and Ergate Leaders cannot be blocked.  This, on top of the Challenge Mode condition of [Enemies have significantly higher ASPD] mean that this stage is a DPS check.  Control and DPS are effective, Tank and Spank is not the way.
• One of the primary challenges of this Map is the Stun of the Sniper Leaders.  With the increased ASPD of the Challenge Mode, this means each Sniper Leader will permanently Stun it's target.  Since Snipers spawn 2 at a time, if they have different targets, that means 2 of your Operators are out of commission.  If they  Stun the wrong Operator at the wrong time, this can also spell disaster.
• There are two ways of handling the Sniper Leaders
  • 1: plan your deployment to control the stun target and minimize it's interference.  With this method we try to keep them both on 1 target as much as possible, and keep them off our DPS.  The Snipers do not have high damage, so an Operator with moderate DEF can survive without a healer.  
  • 2: take them out before they can cause a problem.  Since they stun every 3rd attack, you need very high Single Target DPS to kill one before the stun.  You'll need 1 for each Sniper you want to take out.  Operators like Skadi or Projekt Red might be able to do the job (I did option 1, so I didn't experiment too much with this one)

• 1 Skill-DP-Recovery Vanguard, with their Skill 1 passive regeneration equipped.

• 3 Snipers.   Single Target Snipers are preferred, highest consistent DPS possible, and physical damage. Basically, we want the highest ranged physical damage we got.

• 1 ST Medic

• 1 Physical damage melee DPS that can block at least 2.

• 1 Other high physical melee dps Operator.

• 1 Push or Pull Operator, which will be our Stun soak. FEater or Rope are preferred.

• 1 Operator to serve as our backup soak.  Anything with at least block 2 should be a safe choice, I went with a Healing Defender.

• 3 Flex.  If you are trying to kill the Snipers, these should be the Operators that are trying to do so (eg, Skadi or Projekt Red, any physical melee with high ST damage on deploy).  otherwise I would recommend having back-ups for your melee dps and backup soak, as they are the most likely to die.

Here is an example of the team I used:

Unit placement can be seen in the image below, and deployment order should be done as presented.  Each Operator can be placed as soon as there is sufficient DP.

Deployment Order: 

1. Siege - Skill-DP-Recovery Vanguard with S1
2. Platinum - ST Sniper
3. Meteorite - AoE Sniper (but ST is preferred)
4. Kroos - ST Sniper
5. Shining - ST Medic
6. FEater - Pusher (any Shift Operator should work)
7. Franka - ST physical DPS (Can be faced up or down)
8. Specter - block 2 (or 3) AoE Guard

• FEater is going to act as our Stun soak.  It is important that she gets placed after our Medic, but before the top Sniper spawn takes its 3rd shot.  The first pair of Snipers will emerge at about kill 3, pause for a bit to taunt you, then start moving forward.  The Shift Specialists should have enough DEF and evasion to survive the sniper fire.  If not, bring a backup as one of your flex.  If your DP generation is higher, or costs are lower, you may be able to deploy the soak later in the order. 

Once we have enough DP, we will retreat Siege and deploy our backup soak.This soak will take the Stuns after the Snipers have passed our Shifter.  If you want to try to get fancier, or if your dps isn't high enough otherwise, you can try retreating your Shifter when it is about to leave the first sniper's range (at D6 on the map), and deploying a flex operator to create a new target on the right side of the map.  I didn't need to so I didn't bother.  This goes for the second set of Snipers as well.

If our DPS is high enough, this should take us through to the end.  A few things to keep in mind:

• At about kill 33 two Agent Leaders are going to take the short cut and slam into your melee (where I have Specter placed).  They hit hard and reduce block by 1, so this can be dangerous.  It is a good time to use a cooldown.
• The very last enemy push has 2 Rockbreaker Leaders, so be ready with cool downs then as well if you can.
• If you are having trouble with the stuns, experiment more with your Stun Soak.
• If your melee are dying, you probably need higher overall team DPS.

Enjoy the OP!

* This site was used to create and share the map formations.