People still don't understand how MHA durability works. MHA has one of the clearest split durability system. Every type of durability could be its own quirk.
- Piercing: Hardening quirks - Kirishima, Tetsutetsu, Crust, Crimson Riot
- Elemental: anyone with an elemental quirk has insane resistance against said element e.g. Kaminari
- Blunt force: everyone has this to high levels, even Aizawa, quirkless Deku, Knuckle Duster, etc. This is just more or less fictional characters being more durable. But there's those higher than other's e.g. Endeavor. For quirks, there's people like Muscular & USJ Nomu Force Absorption quirk.
Endeavor for sure does not have piercing durability. I'm sure even an ordinary bullet would pierce him let alone AFO's tendrils. He has split durability more like Wonder Woman, compared to let's say all around durability (Superman).
If I were to class his durability it would obviously be: Heat durability (peak) -> blunt force damage durability -> piercing (would be the lowest).
Most characters in the verse have low piercing durability apart from people with actual hardening quirks. Apart from that, Shigaraki tanked AP shot so one could say he has piercing durability. As for OFA, All Might was stabbed and dragged by AFO's tendrils in Kamino but his back didn't get pierced so you could say his piercing durability is great.
But you can use Deku as an example to see that it takes a lot (of %) for OFA to achieve piercing durability cause 5% Deku can be cut by sharp objects and 8 - 20% Deku can still be pierced by sharp rocks. So lower % percentages of OFA do not have as good piercing durability.
Of course it also depends on the object being used to pierce. I'm sure AFO's tendrils are above any normal weapon.
