71720 Fire Stone Mech

I like LEGO® and I like mechs, so it’s no stretch to figure that I like a good LEGO mech set. Add to that the handsome minifigs in this set, and I had to have one.


It’s a big, lovely box. All kinds of furious action to whet the appetite.


It’s a heft box too, with 968 elements in eight bags. The red and grey color scheme is on display here, and we can also see that some of the bags are predominantly one color or the other.

instruction book & sticker sheet

A single beefy instruction booklet which was bagged with the sticker sheet for protection. I’m happy to see that the sticker sheet is fairly small, as I’m hoping that the model will still look good if I don’t apply them.

Newer instruction booklets have a QR code on the cover in the bottom corner. Scan it, and you’ll be prompted to install a LEGO app for instructions. This is an interesting new feature, but what I’m hoping is that LEGO uses these as a way to distribute alternate instructions and other bonus content.


The first bag starts off with a great minifig. This new version of Cole, the earth ninja, has armor, a shield, and a huge brick-built mace. The masterpiece here is the amazing print on this shield! I also appreciate the dramatic brick-built weapons for this series, they really amplify the D&D themes.

The adventurer Cole has gorgeous prints front and back. The metallic highlights are great here. I appreciate the small touches here, like the one bare (yellow) arm, as Cole tends to like his sleeveless shirts.

bag 1 interesting elements

There are a few new elements and recolors in the set. Here in bag one, we’ve got one of these oversize swords that I saw in 71718 Wu’s Battle Dragon, except that this one has the opposite color scheme!

bag 1 build

We’re just getting started with the first bag, but it is a great start! The sword has a stand and the core of the mech’s torso is built. This is a really solid build already, with a number of SNOT techniques locking everything together.

The bad guys appear together in the second bag. These are really fantastic minifigs, even if they are basically identical. The armor is a fun new element as well, incorporating a loop on the front that can hold a knife (or possibly a thin sword). There are definitely some similarities to the Fantasy Era trolls, but I can’t help but think of these guys as Orcs. I’m sad that they’ve only made one set of elements here, as even an alternate head would have gone a long way for variety.

bag 2 interesting elements

Some great recolors in bag 2! I really like that canopy in transparent orange and new pearl gold elements are always welcome. I don’t think that I’ve seen this trapezoidal curved slope before. I suspect that it originates in the Speed Champions theme, but it has a great shape and should be useful for all kinds of models.

bag 2 build

The second back builds up the rest of the torso, adding bulk and partially enclosing the cockpit.

bag 3 interesting elements

The third bag has two more elements that are new to me. The smaller hexagonal element was originally introduced for constraction figures, but has made its way into a number of systems sets in the last few years. The larger curved slopes have a great plating detail that would be difficult to brick-build. These are new this year and appear in this set in two colors (of which the red is unique to this set). I’m already thinking of some great use for these in a model of my own!

bag 3 build

The third bag builds the one of the legs. This is a big, solid leg, but it only articulates at the hip and ankle, and even then, the range of motion is restricted. The designer has done this so the finished model can stand more easily, but I am always disappointed to see this lack of articulation.


This new ‘Hero Kai’ shows up in the 4th bag. He’s as fantastic as Cole, in his armor with a brick-built sword.

Though not as complex as some of the others, these are some great prints. I really like the similarities between the ornate chest plate and the shield.

bag 4 interesting elements

Bag 4 gives us some of the same elements as bag 3 did, but in new colors.

bag 4 build

Now the mech as two legs. There are some small differences between the two, but mostly, they are just recolors. A decision was made to build the grey knee pad later, which feels a bit weird, but is probably to avoid confusing similar (but different) elements.

bag 5 build

The fifth bag didn’t have much in the way of interesting elements, but it did have both the feet. A lot of SNOT brackets in these. I really like the use of the rocky wedge bricks for the ‘stone’ parts of the mech.

bag 6 interesting

Nothing new in bag 6, but there is an impressive quantity of most of the interesting elements in this set.

bag 6 build

Bag 6 builds the mechs right arm. There is a lot to like about this chunky arm. It has a cool articulated shoulder pad built in, but lacks any wrist articulation.

bag 7 interesting

Bag 7 has a lot in common with bag 6, but I’m excited about this printed version of the rocky wedge brick. These showed up in one set last year, but this is the first time that I’ve seen one and they provide a cool visual effect that would be very hard to brick-build.

bag 7 build

The other arm is a bit chunkier and has a much bigger shoulder pad that will jut out from the model. There are also a pair of integrated stud shooters to boost the play value.


Honestly, I think ‘Hero Nya’ is the best fig in the set. The armor is detailed and functional looking, that shield is dynamite and her brick-built spear is top-notch. This is a fig that I wouldn’t mind getting a few extra copies of!

The front and back print on this torso is fantastic.

bag 8 interesting

The last bag has a smaller bag with all those cool golden weapons in it. Those are going to be great for brick-built weapons and details. That printed shoulder pad element is great too, though I might struggle to find a good use for it.

bag 8 build

The final build is the mech’s head and swords. This is also where I built the missing knee pad, but I forgot to put it in the picture. The head has nice details, but again, I think it suffers from lack of articulation. I much prefer a mech that can look from side to side.

final build

The finished model is big and impressive. I really like the size and solidity of this mech, which mostly makes up for the lack of articulation. The selection of minifigs is top-notch as well.

Another great set. The price per piece is good at just a hair over 7¢, though this set is a bit miserly in the realm of extra elements. It feels like sets in the last couple of years have reduced the number of spare elements where possible.

Anyway, that’s just a quibble. If you like big mechs, this is a great set, with lots of inspiration and technique to enjoy.

Keep building and enjoy!