"Isn't that obvious?" Owen retorted to Finn without hiding his irritation, "Is Diana now at the master-tier, or perhaps even the grandmaster-tier?"
Finn shook his head, "Still diamond."
"Why?"
"The ascent to diamond-tier was too rapid for lady saint. Her teachers said it wasn't good to advance so quickly; they needed her to consolidate her skills. So, they locked her arcanergy."
"I see."
"This locking isn't about stopping the growth of lady saint's arcanergy but preventing it from breaking through the Tier Barrier."
"Hence, over time, lady saint's arcanergy has been continuously accumulating. I don't fully understand to what extent it has grown."
"I see... Wait, what's a Tier Barrier?"
Owen was clearly confused, struggling to grasp the concept.
Finn seemed surprised too, "Mr. Owen, you haven't encountered it? It's like an invisible 'film' that one encounters during a breakthrough in arcanergy, that's the Tier Barrier."