D.gray-Man - Chapter 253.5

so the adult lavi from the previous chapter is reborn as the little guy right?
7 years old lavi got hit by stray bullet almost died, someone stop time and save him.
18 years old lavi then meet the reborn Allen for the ‘first time’

So far, that’s how I understand it. this pointed to us that adult Lavi died around 19 years prior to the start of this story.
so the question is: is this someone the mixture of “Helix Allen-Lavi”?
Their energy did combine to fend off the innocence berserk and apocryphos from…was it from devouring or killing it is the more correct one?

Anyway from the looks of it,

• once upon a time, Original Allen got hurt badly in the war and dying.
• Nearby, Nea somehow got injured after his fight with Akuma etc (from the text, but his look from the drawing seems fine to me) and thus ask dying Original Allen to make a contract and become his new Host. So I would assume his previous vessel died in the war or something.
• and then apocryphos somehow got Original Allen and change his memories. His body were probably change too based on the previous chapters dialogue, but from this chapter, these 2 latest chapter, it seems more like in the process of Lavi saving Allen, his body regress to that of a kid.
• Thus, we get the ‘Contemporary Allen’, a reborn Allen which we now know since first chapter. i believe it was this version of Allen that got to know Mana, the clown and Allen, the dog.
• From here, we can see that Mana somehow knew Original Allen in the past. Not sure the specific timeline, but it was definitely after Nea contracted Original Allen and before Original Allen died by the hand of apocryphos.

Well that’s based on the last dozens chapters or so. Though it has been a while since I read from the beginning so I might miss the timeline.