User blog comment:IamJakuhoRaikoben/Chapter 487: The Third Seal, Review./@comment-84.151.152.141-20160602225158/@comment-7418318-20160604063611

I guess with (by himself) the anon might have meant that the CSK will self-summon, like he did in the Loke-mini-arc. But I doubt it'll happen.

I also don't believe that Lucy will break another key in this situation. Now that she knows that any broken Zodiac Key will regenerate in less than a year she might be a bit less reluctant to break them, but even so it'll be a last resort. I think she'd rather die than break another key, but might be willing to do it if more than just her own life is at stake.