Ash Echoes - Boreas Dupe vs Feng Dupe Guide

Which to Choose?

Ву Regalios.

Boreas Dupe 1 (Seed 2 Boreas) gains an additional trait that reduces enemy Ice resistance by an additional 50% while they are on ice zones. Boreas already reduces 20% ice resistance, therefore dupe Boreas effectively reduces 70% ice resistance. This will greatly boost the damage dealt by ice DPS characters.

As it happens, the next banner after Boreas is expected to be Feng Jr., an Ice DPS character. Most of her damage comes from her skill 2 which can switch between gaining critical hit chance or ignoring enemy DR. Her dupe 1 (Seed 2 Feng) grants an independent multiplier of 20% for each summon (2 total) on field upon a critical hit OR upto 50% reduction in enemy DR for skill 2. Independent multipliers are very good in this game because they effectively interact multiplicatively with all the multipliers (whereas normal multipliers like % ATK increase will interact additively with the other % ATK increase bonuses).

I’ve compiled the damage numbers for single instance of skill 2 in multiple scenarios to help us understand if duping Boreas or Fend is better for overall damage.

Ult skill 2: Feng’s skill 2 damage after her seed skill.
Skill 2: Feng’s skill 2 damage only.
Skill 2 + summon: Accounting for her summon damage when she uses skill 2.
Skill 2 + 10 ER: Skill 2 damamge when the enemy has 10 ice Resistance.
Skill 2 + 10 DR: Skill 2 damage when the enemy has 10% DR (Damage Reduction %).
Skill 2 + 10 DRx (mn / max): Skill 2 damage when switching to her ignore DR mode. min damage when she does not crit. max dmg when she crits while on this mode.

Note: Boreas 1 = Boreas 1 dupe.
Boreas / Boreas 0 = Boreas no dupes (just single copy).

Conclusion

Why is investing in a Boreas Dupe better?

Increases the overall damage for all ice echomancers, so if we get a ice striker DPS (not Ivana or Begonia) in future Boreas dupe 1 is extremely useful.
When enemy has high Ice resistance, having 50% additional ER reduction from Boreas is more valuable than the independent multipliers from Feng.
With the current MT and team setup Boreas dupe does slightly more dmg than Feng dupe.

Why is investing in a Feng Dupe better?

Boreas Dupe 1 is useful only when the enemy is on ice zone. Although the ice team can form a lot of ice zones , especially with help of a water zone, it works well only in wet environments.
ER reduction has a maximum cap of 100%. Boreas dupe increases ER reduction from 20% to 70%. (less future proof)
If and when we get MT’s / skills that help Feng reach 100% crit rate while on her ignore DR mode, she’ll do 14% more damage than Boreas dupe.

Verdict

In my opinion, there is currently no significant difference in advantage between the two options. For DPS puritans, it is probably better to invest in Feng dupe 1 over Boreas dupe 1 because there will be a future MT that fulfils Feng’s 100% crit needs and puts her on the lead for total damage as seen from the last column in the table. Even now “Rewarding Persistence” nexus skill can help Feng stack up her crit chance to forego having to rely on “Patrol” mode and Boreas buff to reach 100% albeit inconsistently.

That said, Boreas 1 + Feng 1 is without question a better investment than Boreas 0 + Feng 3. And do not bother getting Boreas beyond dupe 1 unless a whale or you really really like the unit.