Avatars:

Avatars are similar to MTG commanders, but they are not cast into the battlefield, and they set your Time (life) for the game. Avatars can even grant unique win conditions.

Avatars have effects which can be used at any time as long it has the requisite Energy.

You can add Energy (Energize) your Avatar once per turn by tapping X Energies of the same color which are indicated on the Avatar's Time symbol.

Most Avatars can be Energized by 3 of 6 Energies, so not all Avatars work with all decks.

Picrel Avatar, "Wojak" can be Energized by the Purple, Violet, and Blue colors.

There are 4 Avatars which can be Energized with any Color.

Avatars generally have some sort of generic card draw effect, and then other effects which correspond to the elements which comprise their compatible Colors.

You can attach(Fren) cards to your Avatar, and Avatars can be nullified (temporarily remove their effects).

Identical decks with different Avatars may have vastly different approaches to gameplay.

When your Avatar's Time reaches 0, you loose.

"Avatars" are sort of like commanders in mtg, but you don't ever cast them into play, and also they set your life for the game (it can vary by avatar). sometimes they give unique win conditions.

instead of casting your commander like in magic, you instead spend energy (mana) to put energy on them. you can then use this energy to use their effects.

avatars can only be energized by 3 of the 6 main colors, so they only fit with certain deck color compositions.

they generally have a generic card draw effect, which basically allows you to never waste mana,

this avatar, "Yakub" is pretty good. he can transmute energies (mtg lands) into entities.

the reason this is such a powerful ability is that because there are no dedicated energy (land) cards, you can just play your best card as an energy, then transmute it from the energy (land) zone, into the entity (creature) zone, even if it's a structure or meme.

another reason why this is power is that you could play without any explicit entities (creatures) in your deck, and instead just rely on transmuting non-entities from the energy zone, or frenning together non-entities into the entity zone, as an entity.

this a way to cover a deficit in the fire element during deck construction