User blog comment:RedBack 12/Here's something you might want to see.../@comment-177.129.50.236-20151129191742/@comment-226878-20151129201439

I thought the confusion was more about the implications of said display of skill. Weiss generating a sword or fist of ice meant absolutely nothing to us because it was simply a construct, like anything a Green Lantern can pull off. There were no hints or implications in the prior volumes to indicate that Weiss could summon creatures to her aid, so there was no place to speculate. Why would we bat an eye at something we know nothing about?

People lose their shit over Weiss summoning the Knight's sword because now suddenly Winter is cramming down our gullets that Scnhee's can summon and specifically can summon fallen foes. Knowing that Weiss has defeated that Knight and seeing the sword summoned by episode's end, it is an obvious foreshadowing that of all the creatures she's faced, it is now implied that he Knight will either be the first or her most powerful (it's a staple to imply the ability to summon something OP but never actually summon it until further along in the story).