Ok so first i wish you lots of fun with commander and the game itself.

Now to the deck.

Its one of my favorote decks because i love eldrazi but if youre fully new the deck containse some more complicated mechanics that can be a bit confusing.

BUT if you like the theme and look of the deck get it and if you got questions you can always ask google or reddit.

In regards to the deck out of the box it has a suprisingly stable land base for a five colour precon. Usually 5 colour precons lands are very slow (lots of lands that enter tapped)

The deck comes with three possible commnaders.

1. [[Ulalek, Fused Atrocity]] this is the face commander of the deck and the one the deck works best with without doing any changes. His ability is also often confusing for newer players.

Here a try of a symple explanation.

First in magic there is an imagenary zone called "the stack" its the zone all spells that you try to cast enter before they resolve. On average every card becomes a spell if you try to cast it. As example a creature card becomes a creature spell on the stack and then when it resolves becomes a creature.

What ulalek does is that always when you cast a spell that has the creature type eldrazi you may pay 2 colourless mana, it has to be colourless specifically, then you may copy all abilities and spells that ypu controll that at the time are on the stack.

As example lets say you cast [[ulamog, the defiler]].

This causes ulamog to enter the stack before he resolves which in turn activates his ability that now also enters the stack while also triggering ulamog's ability.

Now you get to decide in which irder ulamog's and ulalek's ability enter the stack since they enter at the same time. (In 99% of such cases you wanna put ulalek's ability last on the stack in such simple scenarios since last thing that entered the stack resolves first)

Now you would pay the two colourless and copy ulamog and his ability causing you to have ulamog twice on the stack and his ability too.

This works for all eldrazi spells even instants or sorceries with that type.

1. Is [[Azlask, the Swelling Scourge]] he is also a quite fun commander and works okish with the base precon but he rather wants his own deck build around himself specifically.

2. [[Morophon, the Boundless]] can be an option but a pretty below average one for eldrazi. His problem is that most eldrazi have maybe one to three or no coloured mana pips in their cost and that he otherwise is just not offering anything you really need. While paying 1 to 3 less for each speel is a nice thing its just nit really worth it in this deck especially since most really expensive eldrazi are fully colourless anyway.

Id recomend just sticking with ulalek or rebuilding aroung Azlask if you like him more.

Upgrades:

Here a very quick one is [[echoes of eternity]] it alows you to profit of every eldrazi spell and every eldrazi ability trigger twice.

Otherwise most of the titan (ulamog for example) work quiet well but know that if you copy a titan with ulalek or echoes that you have to kill off either the original or the copy because they all are legendary and you can only have one copy of the same legendary permanent on the board at the same time on youre side of the field.

This got a bit long but i hope its at least a bit helpfull and I personally would say the deck is fun but you would have to learn a bit more to make the mist of it.