Not sure how I should do anything as this is my first time posting and starting a new topic.
Well this is mainly done as a way to determine the characters personalities and motivations. The greatest villains are not those that are bad for that alone. They are those with motivations and those that makes us think and question our ideals. So here are I will write about what I think the three brothers main characteristics should be. I do not think Ekimu should be considered as a villain side, hence the personality he has is terrible for that but that is later.
It is important to note that I am using MBTI personalities as guidelines but like a normal human, the characters do not have to fit the template perfectly.
So here we go:
When the brothers where born they were bored in the infinite nothingness. So they decided to create the world.
Makuta made the Rahi and plant life. Using careful planing to build the ecosystem and balance it. Striving to achieve an ideal world.
Ekimu made the matoran. Curios about his ability to understand and intelligence, Ekimu tried to replicate it. Creating companions as a way to ease their lone solitude.
Karzahni if he exists made the elements. The chaotic forces of nature that create change and anarchy.
Makuta is somewhat of a planer, so having a mask that allows him to control everything he cannot foresee is a good fit. Makuta at his original strength could control everything. From space to time.
Ekimu is a more sociable creative person. Using the mask of creation he has endless ways of satisfying his curiosity, as well as the flexibility to accomplish any task. Without the need to go through the planning.
Karzahni if he exists would have the mask of power. With a need for anarchy and motivation that makes sense only to him, he just needs the power to accomplish his objective.
If Karzahni is not here, then the main conflict arises when Matoran start disrupting the order Makuta created. Alternatively, the inability of his brothers to understand him make him lead him to believe that consciousness is a curse. Pitying the Matoran for their ability to doubt themselves and question their existence and actions. Any other reason can work as long as it has a logical reasoning behind it. As Makuta himself is logically driven being.
Either way, this will incite Makuta to plan a solution to the problem, leaving him in conflict with Ekimu. Ekimu will search a peaceful resolution to this problem, according to Makuta's plan, however the result will be Ekimu's fatal wound. Since Makuta is unable to consider or give high value to emotion. Which creates a flaw on his plan. Near death Ekimu still searches for a compromise to resolve the conflict thus he creates a matoran body that traps Makuta, so that he can walk in the shoes of others and maybe understand them. Makuta in confusion upon this action and seeing his brother about to die, controls time and stops its flow around Ekimu to prevent his death. Centuries later, Makuta is searching for a way to relieve his brother's suffering. Either by killing him or by curing him, the choice is driven by what he learned as a Matoran in those centuries. Either way he is cynical of the Matoran as actual conscious beings and has no qualms over using them for his schemes. Elements were always existing in the chaos of the universe from where the two brothers where born. Only after centuries of existing near intelligent beings like the Matoran and the threat of Makuta altering the balance (basically changing fate, reviving the dead, stopping time) do they take the traits assigned to them and take consciousness.
If Karzahni exists, then he is the main reason for conflict. He is responsible for crating instability and the elemental forces that drive chaos and change. This does not sit well with Makuta who likes to carefully plan everything nor does it sit well with Ekimu as the anarchy causes suffering to his creations. Both team up and win imprisoning Karzahni. However Ekimu is mortally wounded and Makuta uses his remaining power to control time and stop it around Ekimu. This overuse of power reverts him to a figure similar to a Matoran. Then same as always he goes on a journey to revive his fallen brother. Either way, say what you may about Mask of light movie, the idea that Makuta loves his brother very much in his own twisted way is an interesting idea.
If I were to give them MBTI personalities.
Makuta: INTJ (The Architect)
Both an idealist and a Cynic. He believes that perfection can be achieved but that people are to dumb, lazy or uncaring to achieve it. Perfection can only be achieved if everything is left to him to control. He would also be extremely private and quiet. Acting behind the shadows to manipulate events. His private nature will obviously make it hard if not impossible for him to trust the Toa with his plans or the danger Ekimu is in. Either way his cynicism will ensure this becomes hard as he will not be able to trust them until proven beyond doubt they are competent. His cynicism will also interfere with his ability to see creations as actually conscious beings. Denying their actual emotions as simple pre-programmed responses. Seeing everyone else, other than his brother(s) as complex and fascinating machines not actual living beings. His idealism will drive him to the extremes, not pulling his punches to achieve his ideal result.
Ekimu: ENFP (The Campaigner)
Creative and free willed. Ironically he becomes a leader of sorts tied down by the responsibilities of managing his creation. Always looking for harmony he can see the infinite possibilities that the world offers. He is just unable to follow through them. When he had finished teaching the Matoran about Unity Purity and Destiny, he left to stop his brother leaving them alone in the chaos of the war. He planted the seeds for growth in them but never took the time to actually nurture them. Capable of understanding the feelings of his other two brothers as well as those of his creations he is constantly preoccupied by the friction these different personalities. Always trying to be a mediator of sorts and advocating for a fast resolutions of this conflicts he missed the most logical solution and thus failed to accomplish his objective of harmony. really good at understanding how others feel, he can lift your spirits. Cares more about what drives people than why it drives them.
Alternatively, if you want him a villain. You can always build from this to create a person capable of tearing at the emotions of others making them suffer emotionally of placing them in emotional distress. His manipulation is not based on the logical cause and effect of more common villains it would be based on manipulating the emotional state of others, sometimes forgetting that people can put aside their feelings and act logically. As such his plans would sometimes bee overly complicated and dramatic. He would easily get close to you get the information he needs using his charisma and understanding and then tear you a new one and poke were it hurts when he is done. Unfortunately he would have a hard time deciding how to accomplish his goals and react poorly on fast changing situations. He would have vision of the future with all the ways to acomplish it, just have a hard time deciding which one to pick.
The main reason as to why i do no think he should be considered as a full on good person is because we require a moral compass. Having great villains with justifiable motivations will cause not only us the audience to question or standing but also out heroes. They are going to need a moral compass. Considering that he is not going to appear much anyway, he would be perfect to fill that mentor like role for the Toa. However just because he is good does not mean he cannot be interesting. His personality leaves us with ability to touch upon his flaws. His inability to follow through ideas personally or to deal with conflict appropriately leaves a way for us to develop his character. He might be aware of these flaws and try to mend them, basically struggling to change his attitude or way of thinking. The same way he is a tutor to the Toa, he can learn from his students.
Karzahni: ISTP? (The Vituoso)
Not sure Chaos loving, he could fit into a ENTP if he just wants to show off his chaotic and flashy plan that somehow fits together to create a spectacular result. Showing off and looking for an equally good opponent who may stop him. He would be a villain because it is fun. He would not kill the Toa because they are too much fun to play with. If this is driven by a feeling of being underappreciated, maybe a ENFJ. Jealous on how his brothers would rather involve themselves in things that where not there.
However my favorite choice would be an ISTP personality. With no fear of pulling things appart to put them back together and taking for granted their permissive nature, he would have hard time understanding why his brothers were so upset at him when he decided to experiment in their creation. Maybe his need for validation from his brothers drove him to introduce something they never thought about, chaos and conflict, into their creation after carefully lookig and analysing the end result of his other too brothers.
He would learn from his brothers and try to improve upon their creations. Either to seek their aproval or to determine if those things where viable in the first place. Often building improvements upon the Rahi or attempting to create his own intelligent species. However he would be more dangerous when he joins the battle himself. As opposed to his planing brother Makuta and his peace seeking borther Ekimu Karzahni would be the only one capable of understanding and utilizing his sense to their full potential. His physical abilities are nothing to trifle with. Not necesarily the strongest but with an ability to understand the information transmited by his sense making him a natural fighter. Coupled with his ability to store information until it can be used at a crucial point make a quiet balanced and villainous charactrer. Ussualy, keeping his emotions on check he gives the appereance of a lone wolf. Quietly he conserves his energy analysing his opponent until the opportune time comes when he releases it all in a chaotic display of destruction and overwhelming force. Like a storm he would brew over a time before unleashing its strength, often surprising anyone who does not know him well enough. This would add to his unpredictability. When he is quiet is because a storm is brewing.