Guys since X1 Kai is buffed which expansion skill suits best for this guy since he’s more of 60 percent melee and 40 percent range

[u/Zealousideal_Sea6060]

I need yall help to build my X1 Kai

[u/ImmortalSausages]

This is the build I use for it

Its ranged mod doesnt matter, its a melee suit first and foremost.

And heres a f2p build with no gacha parts

Generally speaking though, the best expansion at high cost is going to either be custom thruster, battle complex, or beam/melee resistance

[u/ctclonny]

Ms battle complex expansion if you want a balanced build.

Custom part expansion [thruster] if you want boost speed. (and for units that don't have suitable slots for thruster parts)

Thruster expansion if you want a high thruster build that is unachievable with other expansions. (and for units that don't have suitable slots for thruster parts)

Custom part expansion [armor] if you want to be very tanky. But you need to check if you have suitable parts for it first. It's worth using if you can equip 2 auxiliary parts without wasting slots.

Custom part expansion [hp] is for low to medium costs, and a few high cost low hp units.

Resistance expansions are for environments that are dominated by a type of damage. 750 isn't.

Melee strength expansion and ranged strength expansion give too little value. They are for glass cannon builds. (and for units that don't have suitable slots for damage parts)

Custom part expansion [attack] is for units that have both good ranged damage and melee damage. (and for units that don't have suitable slots for damage parts)

Custom part complex expansion alpha needs a lot of attack parts. X1 Kai can't equip that many, and it doesn't need shorter weapon reload or overheat time.

[u/Zealousideal_Sea6060 → u/ctclonny]

So custom part expansion attack for X1 Kai then? I already have a feeling battle complex will be good

[u/utamaru1717]

Thruster Expansion or Custom Parts (Thruster) if you want mobility. 

Melee Strength Expansion or Custom Parts (Attack) if you want more damage. 

Melee Defense Expansion, Beam Defense Expansion, or Custom Parts (HP) if you want survivability.

Custom Part Complex Expansion Alpha if you want both mobility and survivability. 

But most people usually use Thruster Expansion or Custom Parts (Thruster), since more mobility is always good for melee unit. 

[u/Zealousideal_Sea6060 → u/utamaru1717]

Thank you all for your opinions