Secondly, armor spiritual and physical will now mitigate debuffs of the appropriate type. This will serve to make spiritual pen more important and to make armor builds less likely to just get cheesed down trivially by debuff builds. Probably be more system adjustments coming down the pipeline
I don't inherently object to the system working like this, but I'd like to again bring up the "buff" problem here.
This weakens debuffs. Debuffs already have the problem that if they're only as strong as buffs, then buffs are objectively better because buffs don't have to contend with defenses at all. In addition, debuffs are already balanced against attacks by virtue of the part where if you're throwing out debuffs instead of attacking then you aren't actually damaging your enemy. A lot of the time going debuff -> attack can actually produce lower overall dps than just attacking.
Obviously a lot of this analysis is based on last year's system, but the same basic principles remain.
For example: say your stats are equal to your opponent. If you throw out an attack, you have roughly even odds of hitting them, and would do roughly half damage (as a crude rule of thumb). If we have a debuff that reduces their defenses by 1 rank then it would also only have even odds of landing and would be reduced to ~0.5 ranks. Overall, it would take about 4 attacks after landing the debuff (prob 1-2 attempts) for overall DPS to begin to overtake what would be achieved by just attacking. In contrast, a buff of the same strength would provide an immediate advantage, having 100% success and being at full power. Indeed, even if the buff was only half as strong as the debuff it would still arguably be stronger, as again it would have 100% success and so always require only 1 action to set up.
Obviously yrsillar has a lot of room to finesse things in the narrative, and the mechanics should not be taken too literally. However, it does illustrate the basic principle that debuffs *have* to be significantly stronger than buffs to make sense as a build path. Given that as far as we can tell they are not, in fact, massively stronger, moving to nerf them even more is somewhat questionable.