Use Temporal Fist and, while time is frozen, plant Ion Detonator charges around the Nexo Walker's big glowing weak spot. After time resumes, run away and avoid his attacks and the Nexo Warriors while waiting for Temporal Fist to recharge, then do it again. Two or three rounds of this and he'll be down for the count.

There are a few ways you can do this. First of all, those huge white round things that resemble a ball sack are its vulnerable points(somebody had to be sleazy on staff). One way is with your saucer. You can shoot its vulnerable point with your death ray. If you're on foot, then you can freeze time and plant ion detonators on its vulnerable point. It takes 8 ion detonators. You can also use your desintigrator ray and zap-o-matic.

Dude just get full ammo on your ion gun or whatever it is and shoot that mofo's ball sack until the dam thing explodes.

Freeze time and plant ion detonators on the big glowing ball sack,its not much of an answer but its how you beat it.btw are you in sunnywood cause if you are thats what you do if your doing an odd job in shen long you protect it until it blows up the police station then you destroy it

Stop Time (Circle)
jetpack behind the Nexo Walker, use Zapomatic until scene cuts, then when he summons 3, fly towards again, freeze time while in air, and Zap his nuts until the hp reaches 0. and its done.

Freeze time go around it's back and shoot the ion detonator into the family jewels or those big white hanging things.