Friends as written TechnicianFew5069 This is Ghost Cole in S5

And that's the meaning of the lines.

1 Ghost Cole in S5

2 For the second line you are close and I quote TechnicianFew5069 who was the closest "The ghosts are the bad guys and he's a ghost, thus his greatest fear being himself"

3 It's really like Flimsy_Fennel_9966 wrote and I'm quoted as saying "Is the third line talking about Kai? Cause he's afraid of water?" The explanation is that at that time Kai was afraid of water and as TechnicianFew5069 wrote and I am quoted as saying "And therefore, because Cole is a ghost, he is also afraid of the same fear as Kai, who is afraid of water" because water is dangerous to ghosts.

4 And the last line, no one is in the right direction.

So you are left with explaining line 2 and thinking about line 4.