So I took the leak of Onua, straightened it out, and tried to recreate it in Lego Digital Designer with the current CCBS parts.
It seems that Onua's chest is a new mold, as well as his shoulders and the extra bits on the shells. It also seems like the "hammer" he's holding is actually a staff of some sort with a cave-in in the background, giving the illusion of it being a hammer. Oh well.
I could try to do this with the other Toa, but it might be harder to replicate their builds, especially "Omega Tahu", what with the size of the pieces being proportionally wrong on him (unless he's getting a new chest mold as well).