Black pally, Guardian of the Runes, and Valkyrie faith pools

I noticed that all 3 of these units only have abilities that cost up to 3, which means their maximal faith pool is sufficient to cast any of their abilities from level 1. Yet at levels 3 and 5, all 3 of them get increases in their maximal faith pool. This change, because of their skill tree and their limitation to only 1 ability per turn, is literally pointless. Are these maximal faith pool changes reflected in the AP cost? Or perhaps is it planned to have abilities that will reduce a unit's faith as an attack/aura?

I noticed that all 3 of these units only have abilities that cost up to 3, which means their maximal faith pool is sufficient to cast any of their abilities from level 1. Yet at levels 3 and 5, all 3 of them get increases in their maximal faith pool. This change, because of their skill tree and their limitation to only 1 ability per turn, is literally pointless. Are these maximal faith pool changes reflected in the AP cost? Or perhaps is it planned to have abilities that will reduce a unit's faith as an attack/aura?

maybe in the future it will be useful...or there will be a skill similar to occult erosion but that targets faithfuls...What is the problem with that, other than it is not useful?

What is the problem with that, other than it is not useful?

the problem is that you are paying more AP for a pointless upgrade you cannot avoid

but upgrade not only increase max faith point but also range of the 'faith gathered'

but upgrade not only increase max faith point but also range of the 'faith gathered'

exactly this. notice that warrior-monks pay 5 AP only while the true-monks pay 10. The only thing worth discussing is why at lvl 5 this goes to 10 for warrior monks.

[Jigoku]

Let me clarify that point a bit.

Magic (/Theurgic) mastery levels works like this :
* A mastery level of 1 costs 5 AP.
This AP cost is taken into account for every lvl.1 caster unit (because without a magic mastery of at least 1, you couldn't even cast anything). This is usually the starting mastery level of any "hybrid" caster (besides the Chimera).

* A mastery level of 2 costs 5 AP.
This AP cost is taken into account for the PA calculation of lvl.1 "pure" casters (Magicians, Necromancers), because this is their starting mastery level. So every "pure" caster starts at lvl.1 with +10 AP due to their (cumulative) mastery cost.
When a warrior-mage or warrior-monk gets to level 3, it usually gains 1 point of Mastery (getting to this mastery level), which increase their cost by 5 AP.

* A mastery level of 3 costs 10 AP.
This is the starting mastery level of the Chimera.
This is also the level that "pure" casters attain when they hit their level 3, and that "hybrid" casters attain when they hit their level 5.

* A mastery level of 4 costs 10 AP.
Both the Chimera at level 3 and the pure casters at level 5 get to that mastery level, and pay that price. With the exception of the Chimera, no hybrid caster can attain this level.