Long Post incoming...
I am legitimately confuse on why this is recommended over Spd +3 sacred seals. I have done the math & scenario in my head, and I don't see the use.
First off, Phantom Spd only benefits the weapon effect, not her Special nor the ability to perform a follow-up, while Spd+3 does. Now someone may argue that Phantom Spd enable for the weapon effect to occur more consistently, and my rebuttal is, it adds nothing for her. I'm going to list many the scenarios with and without Phantom when Ayra cannot perform a follow-up due to Spd.
Now for some notes about these situations, I only use Regnal Astra charge because that is what is recommended with Phantom Spd. And lastly, the reason why I'm only looking at situations in which Ayra cannot perform a follow-up attack is because if she could naturally double, she is already activating her weapon effect regardless of Phantom Spd.
If Ayra attacks while her special is charged at 2, and foe can counter-strike:
- With Phantom Spd, first strike reduce charge to 0, and foe's strike will keep charge at 0.
- Without Phantom Spd, first strike reduce charge to 1, and foe's strike will reduce charge at 0.
If Ayra attacks while her special is charged at 1, and foe can counter-strike:
- With Phantom Spd, first strike reduce charge to 0, and foe's strike will keep charge at 0.
- Without Phantom Spd, first strike reduce charge to 0, and foe's strike will reduce charge at 0.
If foe attacks first while Ayra's Special is charged at 2
- With Phantom Spd, Foe's strike will reduce charge to 1 and then Ayra's counter-attack will reduce it to 0
- Without Phantom Spd, Foe's strike will reduce charge to 1 and then Ayra's counter-attack will reduce it to 0
If Ayra attacks while her special is charged at 2, and foe can't counter-strike**:
- With Phantom Spd, first strike reduce charge to 0.
- Without Phantom Spd, first strike reduce charge to 1.
*Phantom Spd does something!!*
The only situation in which that wouldn't be true is if the opponent ran Phantom Spd, but that is unlikely because Phantom Spd is basically useless in most situation. But let's actually consider that situation with 2 Ayra, one with Phantom Spd with the other with Spd+3. *Assumption is that both have same stat lines and have same builds (i.e, running Swift Sparrow) except for seals.*
**Ayra with Phantom Spd = Phantom**
**Ayra with Spd +3 = S.Ayra**
Phantom initiates attack against S.Ayra
- Phantom fails to double as Spd is not greater than 5, but proc weapon, reducing charge to 0. S. Phanton's charge reduce to 1.
- S. Ayra attacks back, and charge is also reduced to 0. No change for Phantom's charge.
**S.Ayra initiates attack against Phantom**
- S.Ayra doubles due to Spd greater than 5, but does not proc weapon. First strike reduce charge to 1. Phantom's charge reduce to 1.
- Phantom counter attacks, and charge is reduced to 0. S.Ayra charge reduce to 0.
- S. Ayra follow-up attack, proc Special and reset charge to 2. Phantom charge still at 0.
As you can see, even in this situation, running Spd +3 is the better choice. I must be missing something because I don't see Phantom Spd being useful. Saying, it's protection against those that uses Phantom Spd is also worthless because the only fast unit using Phantom Spd is Ayra herself.
So to end this, I ask, why is Phantom Spd better for her than Spd+3.