Quote Originally Posted by Ryll
Zoltraak? Mana depletion wins the encounter. The Barrier will not break, you just won't be able to produce them anymore and one will slip through.

"Modern" magical technique attacks that hit physically? Strong enough, and they will break the Barrier unless it has been reinforced, which slows down the activation time of the Barrier.
So, firstly let's talk about how you'd deplete a barrier between Zoltraak and shield.

If Frieren fires 100J of Zoltraak, presumably a defender's shield will drain 200J of mana from the defender since the spell's very nature makes it costly (per the inventer of Zoltraak whenever they covered it).

I think we agree so far that shields against Zoltraak seem to never break until the defender runs out of mana. Let's discuss the mechanism. Suppose Frieren's final attack against Denken at the end is a 1MJ Zoltraak (we've seen her fire some spectacularly big ones) - how does Denken use 2MJ of barrier to block this? Did he have to actively cast a 2MJ barrier beforehand (seems unlikely), or does he cast a barrier that automatically drains whatever is required?

If barriers can drain mana dynamically based on the strength of the attack, then why can't it do that against physical attacks? It seems like physical attacks disproportionally drains shield. Using the first scenario, a 200J mana shield might only be able to block a 1kg rock being hurled towards it. Hurling that rock would only cost 50J of energy - so spending 100J on rock hurling would do more shield damage than 100J on Zoltraak.

Now you mentioned that if a physical attack is strong enough that it'll physically break a barrier. How would that work? If shields dynamically drains capacity then physical attacks should just make defending even more inefficient, but should not break with mana left.

If shields do in fact break after a limit then there's no point blocking attacks after a point. If shields are only good at blocking attacks from monsters and warriors (per this episode), then never block a ball of water - be it Frieren or Richter - since that would imply an inherent damage cap to barrier magic.

This is all unless mage output is also taken into account. If Frieren and Denken (who has 1KJ of mana remaining) both can perform 1KW of magic each, an exchange of 500J to cast Zoltraak vs 1KJ of shield would be resolved instantly with Denken now having 0 mana.

If Richter puts in 1KJ of mana into smashing a pillar into Kanne, she'd require 4KJ of shields to block it. If her output is 4KW or more, she'd just deplete her capacity. If her output is less than that (eg 3KW), then the shield would break and she'd take physical damage (but be left with 1KJ of mana).

This would make sense mechanically, but the fact that we've never seen Zoltraak break someone's shield by saturating output alone without depleting mana seems to be oddly coincidental.