Basically there are the four governing energy types, Spirit which is balanced in all categories, Demon which is destructive mostly, Angel has massive energy reserves and control, Impure which has the lowest reserves but negates many abilities.

People can gain abilities, almost essentially like going SSj. Abilities such as unlimited energy, intangibility, teleportation, the power to make a single punch hit many times(sort of like the Nail Punch from Toriko), the power to predict what will happen in a certain radius around them, the power to multiply a single attribute etc etc
Impure energy basically lets people beat out hax, an Impure attack will cancel out intangibility for instance.
Most people fall in to one category, some are a hybrid between two.

As well as that there are 8 "elements" split between 4 colours, each person(haven't decided if they'd be human or whatever, probably for simplicity all English speaking too of course ) has a mark on each hand named a "core", each foot and their chest, signifying the element that part controls. Typically peoples arms will use the same elements as will their legs and their abdomen contains their most powerful element that they can flow through each part of their body.

The cores and their elements being:

Red, Force and Destruction. Force is basically an energy used to enhance attack power or launch shockwaves.
Destruction is essentially explosive energy.

Orange, Fire and Wind. Fire is...well, fire. Burn stuff, shoot fireballs etc etc.
Wind is...wind. Launch wind blades, enhance cutting power, create gales, enhance speed etc etc

Green, Energy and Earth. Energy is fairly versatile, can be used to enhance the amount of energy in an attack but not necessarily it's strength, so a Destruction blast would have a wider AoE but not more explosive force within the AoE.
Earth is fairly simple, move around the ground, add weight to attacks, create golems and such.

And finally my favourite, Blue. Water and Lightning/Electricity(lightning sounds cooler)
Water, fire water jets of varying pressure, create ice if the user learns how to and various other powers.
Lightning/Electricity of course fire lightning bolts, shock people, enhance a users speed if used on feet and abdomen, abdomen and by extension head also enhances reflexes.

The elements can be combined in various different ways for different effects, for instance Fire plus Water can create steam jets. Fire and Earth can create magma.

The elements as you may notice take a lot of inspiration from those in Naruto, I loved the variety the elements gave in Naruto so the series I imagine has a s*** ton of variety naturally.

Finally there is also Pure Energy which create abilities unique to characters, they typically have some control over these. This takes inspiration from HxH's power system.
Usually a Pure Energy ability will work well with a regular ability, they also can be used to damage ability users in a similar way to Impure energy. They usually have a limit on them as well.

Pure Energy has powers such as being able to summon a blade that can cut anything but only once a day. Being able to coat ones self in an extremely tough and attribute enhancing armour that in turn disallows them from using elemental powers.

So yeah series gets pretty crazy.