To build a mobile suit, click Build from the deck screen in the picture a bit above. You'll be shown a list of your currently owned blueprints, which are used to build mobile suits. Here, we are going to build a Stark Jegan from a gold blueprint.
Select the blueprint and click build. Any missing materials will be bought automatically.
However, do note the blueprints with the green bar along the bottom of their picture. Those are rentals and while they cost nothing to build, they come pre-upgraded and can only be used for ten matches.
You'll then be asked which ticket to use. Building and upgrading MS requires the use of mechanic tickets. Silver mechanic tickets are plentiful as they drop from battles and can be bought in the shop with GP. Gold mechanic tickets are given out from events often, and one can be found each week in the daily gacha. They can also be bought with BC, but that really isn't needed.
The difference between the two is the success rates. The Yellow number is the percentage for a 'critical success', which will heighten the stats more than a 'normal success', which is the green number. The gray number is the failure rate, which will still upgrade the stat, but at a greatly reduced amount. The further you upgrade a stat, the worse it's success rates will become. This isn't really applicable to building the MS because the failure will always be 0%, but keep it in mind when upgrading the stats later.
After clicking build in the previous screen, you'll be shown a final confirmation box. In this case, I've decided to use a gold ticket to build my gold Stark Jegan blueprint. If using a gold ticket, you can spend additional tickets to increase the success rate.
I've decided to replace the Gaplant on my deck with the Stark Jegan I've just built.
After clicking on it, select the MS Swap button, and then select the MS to swap in.
Next, we'll upgrade the mobile suit. Let's start with weapons.
This is the weapon menu. Mobile suits often have many different weapons to select from, and can equip up to three at a time. Many of these weapons come in multiple variants as shown by the letter at the end of it's name. The vulcan pod system in the screenshot for example, comes in a normal variant, a H variant and an M variant. Despite these being separate weapons, you can only have one variant equipped at a time. The number listed on each weapon is the weight.
Also, while weapon variants need to be unlocked in order, the base variant can be unlocked standalone. Once you unlock your weapon, you equip it using the equip button which I forgot to screenshot. It's in the same place as the un-equip button in the previous screenshot.
Click Upgrade to be taken to the weapon upgrade screen. In this example, I'll be upgrading this rocket launcher, but not all weapons will have the same parameters to upgrade. Weapons can be upgraded up to 10 times. Each time you select a parameter and use a mechanic ticket, it upgrades the weapon.
We'll upgrade the mobile suit itself. The button to get here is the one I've labeled as Machine Upgrade up above. Upgrading the mobile suit is the same process as upgrading weapons. MS built from silver blueprints (silver MS), can be upgraded 20 times, while MS built from gold blueprints (gold MS) can be upgraded 30 times.
What you upgrade is your preference, however I would reccommend a balance of armour, boost speed and boost capacity. Don't put any points into boost charge, as the december 2019 balance update made all MS recharge near instantly.
Eventually, we'll have a translated module section on this site, but for now you'll have to ask on the discord what modules to go for. Modules enhance the MS and can do all sorts of things, from increasing accuracy while moving, to reducing boost consumption while melee-ing to even increasing the speed which repair pods are placed down. The more expensive an MS, the less modules it can equip. The Stark Jegan only has three available slots. Equipping modules also increases the mobile suit's re-spawn time.
The passive ability is assigned when the MS is built. It is randomly selected from three possible passives as displayed on MS's profile screen, and cannot be re-rolled or changed. Silver MS start with a level 1 passive, while gold MS start with a level 3 passive. The passive can be leveled up by feeding it additional blueprints of the same MS. Here, I happened to have two silver Stark Jegan blueprints lying around, so I'm using them to work towards upgrading the passive to level 4.
Some MS have a lot of paints to choose from, some only have the three mastery paints available, and others, mainly ace units, have no additional paints available and can only apply an emblem.
The emblem is applied to a fixed location the MS and cannot be moved.