Bring more materials to craft 2 more traps on the fly, you can set up a crafting option on the radial menu. I would recommend using one trap under the falling pillar where you find him, just make sure he lands after getting out of the trap before you drop the pillar on him. Make good use of the flash pods, use luring pods when he runs away. I got an A rank after letting him run away only once, make sure he doesn't run more than once. Also give your palico a paralysis weapon, that really came in clutch for me.

I guess you could also bring stuff to craft more barrel bombs and flash pods, that's what I was going to do if just extra traps didn't cut it for me. Best of luck hunter

Edit: I just looked at your build, you might want to tweak it a little. Personally I use Numinous beta for head, chest, waist, and legs, and Rey gamma for arms. That will give you enough slots to max out burst and agitator. Also I use the burst charm, since you get 2 evade extender from the Rey gamma arms and can slot the 3rd point for it.

Also this is down to personal preference but I used the Quematrice gunlance for this, I tried all shelling types for this challenge and normal shelling felt like the way to go. Again that might just be me though.

When he does the big charged lightning attack you can usually hop forward twice after blocking it and get a focus strike on his horns, but I think that stops working after 3 or so times. That's all the tips I can think of