can someone please explain what happens to cibo and iko in detail

They are dead...
Iko used all his energy (including life) to help Dhomochevsky shoot again, and Cibo turned to Level 9 SG unit and when Killy shot C1 Exterminator with L4Ex GBE shot, everything was destroyed except Killy - so C1Exterminator, Cibo and Sanakan - R.I.P.

I understand that but I dont get when Iko goes inside that tank with the bubbles and when Cibo connects to it. What is it? How did Cibo turn into the SG whats up with the kid inside?

That was happening when they connected to Davinels matrix... everything that was happening there is in virtual world - that kid is Iko - that is how he looks like in reality, but he doesnt have body in real world... Iko connected first to open a way to Killy and Dhomo so they can kill Davinel before he enter Netsphere, but Cibo connected too - and that is about that room and kid - Iko was there allready to prevent Davinel to connect - when Davinel stole L9SG. Iko entered in Dhomo to give him power, and Cibo assimilated L9SG program and transformed...
You know the rest... ^^

Just wanted to add something, thouh I'm not sure about that.
I didn't got it at first, but i looks like the weird thing in front of Iko in the virtual area is the virtual repersentation of Davinel, it look a bit like an SC head, and whenDavinel is dead, this sort of head falls deep in the dark.
Well it just helps to represents what happens.

But why did Cibo connect to Davine's matrix when Iko has already been in the process to open the gates? Just before she connects there are a few panels where she hears a loud noise (VAZSHH) coming out from the terminal which Iko connected to so she calls Iko with a worried look on her face then she starts contemplating what to do. Was she worried something happened with Iko or did she intentionally connect because she wanted to see the Netsphere?

Also, the end of this chapter is totally confusing. After Dhomochevsky shots Davine we see his last moments in the Netsphere. He almost collapses, but regains his balance in the last second, then the Admin says:
"This is an entirely unexpected situation for us. On the verge of death, Davine Lu Linvega managed to steal data of a highest level safeguard unit. Your previous self will cease to exist. How very regretful."
But it clearly can be seen that Cibo steals the LV9 safeguard, not Davine. When Cibo connects to Davine she right away starts tampering with a sphere, most likely this is the data of the SG.
But if really Davine steals the data why didn't he download it into his own body to save himself? This is exactly what the Admin implies as well by saying "Your previous self will cease to exist".
The SG should have regenerative abilities and his body seemingly didn't incur so heavy damages it couldn't been repaired like instantaneously. What is the point of downloading the SG into Cibo?

i made sense of some parts of this thing, the ones i couldnt i just go
'well, it's nihei ¯\_(ツ)_/¯'