I posted my thoughts on their encounter in my review for chapter 455, but decided that it’s very important and deserves its own post.
The most important part for me in chapter 455 was what Brandish said to Lucy:
I wonder why you left a rather deep impression.
Now, this could be interpreted in two ways.
Lucy left a rather deep impression on Brandish. It could be because of her quite rare Celestial Magic. In terms of power, however, Natsu for example is more powerful than Lucy, so that shouldn’t be the reason Lucy impressed Brandish. If Brandish was indeed talking about herself, the most believable theory is that Lucy’s rare magic impressed her.
Lucy left a rather deep impression on someone else. Remember the picture Mashima posted a while ago? The one with Lucy kneeling before Zeref? It could be the case that Lucy left a deep impression on Zeref and he decided to send Brandish to kidnap her (most probably).
How things go with Lucy and Brandish in the next few chapters will be really interesting. First, Lucy has become very strong and she wouldn’t give up without a fight. Imagine Brandish and Lucy fighting each other with little Marin trying not to get crushed accidentally. It would be epic! It’s possible that Zeref could appear and the “kneeling before Zeref” scene could happen in Lucy’s room. Also, there’s the possibility that Brandish (if she knows) or Zeref (if he appears) could tell Lucy about E.N.D.
We still don’t know whether or not Zeref has come to Magnolia. Him not appearing may be a hint that he’s up to something and I think he’s gonna meet Lucy very soon.
I feel like all the angst theories about Zeref using Lucy to make Natsu turn into E.N.D are actually gonna come true. I just hope neither Lucy nor Natsu gets hurt. Can’t wait to see what else this arc has got for us!