My party people say that the behemoth is the best boss for experience but i find the guard armor is fine too. The only issue with guard armor was the HP but that's valid since you can stun him for 5 turns. So since im level 187 should i lean towards the behemoth or guard armor?

The Guard Armor because he'll give you the most lux especially if you have him at an high enough level

Yeah Guard Armour is the way to go. Because of the multiple parts it has, the Lux you collect is higher than other bosses.

 

Peace!

I'm level 45. Guard armours are what usually help me gain a level or two. But they are also my worse nightmares because of so many moving parts (and my medals are crap )

I'm level 45. Guard armours are what usually help me gain a level or two. But they are also my worse nightmares because of so many moving parts (and my medals are crap )

At least this late in the game party members will have strong medals to share.  Make it easier on you. 

Thanks! Now i can just do 57 3 times haha