Arknights: Guide to CB-EX2 Normal And Challenge Mode

This guide will step through a strategy for clearing CB-EX2 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:

Challenge Condition: The ATK of enemy melee units is greatly increased

There are 2 main challenges in completing this stage:

1. Killing the Ergate Leaders quickly enough, since they cannot be blocked. For this, we will primarily rely on using the blockades to direct them where we want, crowd control operators to Slow and Stun them, and DPS to bring them down.  They have slightly more RES than DEF, making melee CC Operators like Manticore or Ethan quite useful against them.
2. Stopping and surviving the Bulldozers, along with the other enemies that come with them.  These guys are very deserving of their name, as it requires 3-Block to stop them, and they have very high offensive and defensive capabilities.  On Normal mode, it is possible to block them using multiple Defenders.  On Challenge Mode, however, Defenders will be quickly shred to pieces against their onslaught and that of the other Melee enemies.

In the strategy presented here, we will use crowd control and the blockades to implement a no-block take-down.

• 2 Vanguards, V1 and V2, We want to generate DP as quickly as possible, and long term blocking isn't an option.  Our Utility Vanguard Myrtle is the best choice, followed by Block-2 Skill-DP-Recovery Vanguards with their S1

• 2 Supporters, Su1 and Su2, of the Slower variety.  To slow them down so we can take them out.  For any supporters not available, replace with ranged dps.

• 3 Casters,  C1, C2, and C3, AoE Casters are preferred, but but strong ST can work as well

• 1 Medics, M1, ST Medic (Can be retreated after the last Marksman is dead if needed to help finish things off)

• 1 Control Specialist, SP1, either Manticore (I recommend S1) or Ethan (I recommend S2).  If you don't have either of these, then you can try another Ranged Operator of your choice, an AoE Sniper might be worth a look

• 4 Flex (1 for deployment, 3 for backup), The last deployed unit can be any ranged Operator of your choice.  Crowd control, debuffs, high DPS, and AoE are all things to consider.

Here is an example of the team I used:

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

Deployment Order: 

1. V1: Myrtle - Utility Vanguard
2. V2: Courier - Skill-DP-Recovery Vanguard
3. Su1: Istina - Slower Supporter
4. Su2: Glaucus - Slower Supporter (Because of the pathing of enemies, the Supporter range here is particularly useful.
5. First blockade at C7
6. Let the first enemy pass if your V1 can take it, the place the second blockade at B9
7. 3rd blockade at F5
8. Sp1: Manitore - Control Specialist
9. Flex: Pramanix - Debuffer Supporter
10. C1: Ifrit - or AoE Caster
11. M1: Silence - ST Medic (For the marksmen)

Deployment should look something like this:

When you have enough DP, retreat your Vanguards and deploy your final Operators: 

1. Retreat V1, deploy C2 - AoE Caster - Skyfire
2. Retreat V2, deploy C3 - AoE Caster - Gitano

Deployment formation looks like this:

Right around Kill 30 is when the first bulldozer comes into your kill zone.  It is a good idea to save cooldowns and use them at this point.  Our last block we will deploy at G9, just before any enemies will enter the grid.  This will cause them to turn around and head back through the gauntlet.  

As long as no enemies make it through the second time, you win!

Enjoy the OP!