He is called Umarak the Destroyer after all. You can’t be called the destroyer without destroying something. Much like how you can’t be called Umarak The Hunter without hunting anything.
Also, notice how there is a volcano in the background of UtD’s front box art thats erupting a strange liquid (or gas) thats the same color as UtD’s torso? There is also a ton of cracked and destroyed ground on all the beasts box art (including UtD).
If Umarak does blow up/“destroy” Okoto that would be cool to see tbh
Maybe he isn’t destroying the island per say and is instead destroying the harmony between the elements and using the Volcano to re-form the Mask Of Ultimate Power for Makuta - given the mask is either lost or destroyed.
The energy appears to represent the Mask Of Control - Umarak The Destroyer is coloured that way because he is being controlled/subverted by the Mask Of Control. So it appearing in the background is likely Makuta’s attempt at trying to control something else.
I think after his transformation, Umarak The Destroyer will be more along the lines of a beast-like creature that serves Makuta in his goal of regaining the MoUP. I’m still expecting 2016 to end with Makuta gaining knowledge of the MoUP or even perhaps regaining it leading directly into the ‘final battle’ in 2017.
The destruction of the harmony between elements is what could cause the island of Okoto to blow up. I think the ‘final battle’ in 2017 is gonna involve the Mask of Time in some aspect.
That makes sense. Who needs Bohrok when you can get a giant powerful being with one of the most powerful masks to destroy an island, amirite?
Edit: What if the Toa go back in time and mess up the timeline so their masks become Kanohi?
I would be 100% on board with this. It would be awesome to see the Toa fail and also see the use of time travel. And it’s certainly viable considering Umarak the Destroyer has his hands on the Mask of Control and the Vahi exists in this universe.