This means that the Nova Corps who was guarding the power stone is probably not doing so well in this movie.
这就意味着守护宇宙灵球的新星军团在这次电影中没有守护好这颗宝石。
哈利波特与魔法石
I reckon there are other things guarding the stone apart from Fluffy, loads of enchantments, probably.
我猜想,除了路威,大概还有其他机关在守护着那块石头,很可能有一大堆魔法巫术。
英语百科
Guard stone
A guard stone, or chasse-roue (French lit. "wheel chaser"), is a projecting metal, concrete, or stone exterior architectural element located at the corner and/or foot of gates, portes-cochères, garage entries, and walls to prevent damage from vehicle tires and wheels.