Okay, giant Ghiddy's Opinion post coming up, run while you can...
This is more a post about the relation between whichever good major figure you choose, be it Mata Nui, Ekimu, or somebody knew, Makuta himself, and a couple of the Toa, although I will be covering my opinion of Makuta and what he should be like.
Makuta, as portrayed in MNOG 1, was the epitome of who Makuta actually was, in my opinion. Incredibly manipulative, unfathomably powerful, maliciously evil, and unbelievably misled. Most importantly, our first look at Makuta started out as a small, scrawny Tohunga, which was a genius move on LEGO's part, because it didn't make us feel underwhelmed at all, but only intrigued as to who or what Makuta actually was or could be.
Secondly, another very important piece of character we received was that Makuta was, at first appearance and potentially the original idea, stronger than Mata Nui. You can't be weaker and more pathetic than the person you defeat, either mentally or physically. And considering Makuta thrust Mata Nui into a near-permanent state of unconsciousness, he had to have some great advantage. Even to the very end Mata Nui was at a disadvantage, as Makuta always had a counter or a shield to hide behind and cut through whatever Mata Nui or his was doing.
One more thing to consider about Makuta is his actual allegiance. In G1, we found out late that Mata Nui was mostly apathetic to whatever was going on inside him, save for a very few occasions where he tried to do something minor just to throw a tiny wrench in Makuta's plans. I noticed TTV seems to have the opinion that Makuta was a neutral-good character all along, and I have no doubt it will be reflected in their G3, but it should be done carefully without making Makuta look like a stereotype.
Now heading back to G1, we can see the Toa's interactions with Makuta in very different scenarios. Kopaka instantly saw through Makuta's ploy as a Tohunga, while the rest were left baffled by his power play. I don't recall correctly, but I believe there was some small blurb somewhere about Onua being more connected to Makuta than the other Toa or anyone else, and even if this isn't exactly reflected with Onua it should be something kept in mind nonetheless. Another thing to consider is the unusual significance to Gali at random times, not specifically Makuta but other characters and circumstances. That may have been because she was the only female Toa in the original group, or because the theme was winding down and needed to play a few wild cards.
And finally, we have what Makuta actually is. We got to see him become a monstrous-looking being in gunmetal armour, then he became a... Species... And then a dust cloud... And then a 40,000' robot. Clearly the department of consistency wasn't put on the Makuta project. However, it did keep us guessing even though it also made us throw up a little in our mouths at the ridiculous changes. So if you're going to portray Makuta at all, he can never be a predictable character, even in his existence.
To sum up: He's the bad guy but he's not your everyday bad guy by any means, so keep him enigmatic.