The conclusion of this arc might turns out like this: after the tournament, people find out the df is a plastic toy which was used by DD to lure in strong fighters; then on an unknown island in the NW, Coby accidentally finds the real one. In the far future, when Coby is about to become an admiral, he have to against Akainu over the absolute justice policies, hence a fight similar to Aokiji vs Akainu takes place and this time we have a re-match fire df vs magma df. Of course this only happens only after Akainu looses his fight with Luffy but the man is totally a sour looser so he still wants to make lame excuses for his lost, this is when Coby steps in to clean out the hardness of absolute justice.