Ninjago theory's

Zane's heart

Okay, so right now, no one really knows what the deal is with Zane's heart. It was two pieces that separately powered him but he can function with just one of them.

They also hold his elemental powers and were supposably given to him somehow by the original master of ice.

Since elemental power is passed down through genetics, it would make no sense that he just has the powers naturally.

We know that Zane first met the master of ice when he came to his and Dr Julien's home on the woods. They let him stay the night and according to the flashback, we can guess that Zane got his powers around this time.

So what happened and how did he get them??

What I think is that Zane's power source is actually made from chronosteel. (I think that's how it's spelt)

Incase you can't remember, Chronosteel is the only metal that can absorb elemental power. It was used on the hands of time back in season 7.

So, what I think happened was:

The master of ice was getting old and he didn't have a wife or a child of any kind. If he didn't, his power would be forever erased.

That was around the time that he saw Zane chopping wood (or doing something in the birch wood forest idk).

The master of ice could immediately tell that he wasn't like any human he'd ever seen and over the next few days, he watched the boy and came to the conclusion that he was a robot.

He knew that he wasn't going to have a son anytime soon so that meant if he could somehow get his powers transferred to the droid, the power would still be around, probably for much longer than a human.

So what he did was he went to Ray and Maya to see if they had any spare cronosteel (that was shortly after the hands of time battle so they were still around) and it just so happened they did. It was a little misshapen but he eventually got it into the right shape it needed to be.

He then did the hardest part, he gave up his elemental power and put it into the power source.

It was difficult for him to give up his power but in the end, it would be worth it.

He then had to act as a lost old man for Dr Julien to let him stay for the night.

During this time, when he was alone with Zane, he would tell him everything. About being an elemental master and how important it is for his powers to be passed down through him.

He asked Zane if he would be interested in becoming an elemental master and once Sane agreed, he gave him the power source and ever since, Zane has been an elemental master.