Inconsistent storyline, plot & characters

Rating: 6/10 (21 March 2019)

I'm only focusing on the storyline and characters here. The special effects and stuff was great. Acting was bad and there was little character development.
This movie suffers from the same problem common to many superhero movies these days. The hero can be regarded a hero ONLY IN THE CONTEXT of the absolutely stupid plan/purpose of the villain.
1. King Orm wants to scorch the surface. OK but then what? What are they going to do with all that land? They can't possibly expect to rule it. Are they planning to sell the surface to the highest alien bidder? (it would make perfect sense if this was the case) Only the royalists can even breathe on land. 99% of their population can't. There is no resource on land that they crave. They have absolutely nothing to gain through an invasion and a lot to lose. So what's the point?
2. And just because king Orm's plan is absolutely ridiculous, the hero becomes the hero by stopping him. That's the whole story.
3. Now just for a moment, imagine a more sensible plan from the 'bad guy'. Let's say Orm only wanted to unite all the clans (and become ocean master) just so that he can prepare for any possible threat from the above. Let's say he's using the fear/hate for surface dweller only to gain support from the others. Say he never really planned on scorching the surface. If this was the case, can we totally vote for Arthur?
Basically, Arthur is the hero only because the bad guy's plan was just ridiculous.
Now, take a look at the characters...
4. Arthur is not really a hero for Atlantis. He had a little brother down there and he knew it. He says he wanted to visit him but this was clearly a lie as he never even tried. He finally came (only as an enemy) when he thought his loved ones were in danger.
5. Now Orm on the other hand, knows that his brother above was trained by a traitor to take his throne. He also knows that Arthur wanted to do nothing with Atlantis. Orm says he hated Arthur. However, Orm never tries to harm Arthur (or his father) in any way even though he knew Arthur could become a threat someday. Even when Arthur comes as an enemy, Orm still tries to send him back before the combat so that he doesn't have to kill him. So, which one of them is more honest & honorable?
6. Vulko is a pure traitor. He swore to serve the throne but trains the half-breed to take the throne from the pure-blood king for no logical reason. He just sits there and lies to the face of his king on a daily basis. When Orm asks "Why?", Vulko's reply is just laughable. How on earth can he possibly know that Arthur would have become a better king than Orm would ever be WHEN ORM WAS JUST A KID?? He started training Arthur when Orm was even younger that Arthur.
7. When Orm says he had dedicated his whole life to Atlantis, Vulko does not deny that. So there is clearly no reason why he would support Arthur (since the time Orm was just a kid) unless he wanted to make Arthur king based on the Queen's beliefs. Why can't he just say that?
8. If Vulko really served the throne (as he claimed), he could have tried to unite the brothers after the king's death. Remember that Orm had no other family except his brother above. Vulko doesn't do that but just keeps on believing that Arthur MUST be the king they're looking for.