i dont know about Baron but for baltheon bv put his arm on other bot (i saw someone try it with seraph in Niconico, i put mine on pacifer)
you better use stardust cannon on baltheon i think. (thorlar am3 is good too, but it gachapon and currently not available)
edit: for how to use core, you only doing ok in arena and almost useless in epoch.(if you want to stop breaker, tuned 3slot bazooka put it on art bot with alot of fly is better)
-Milaly/decent alpha air or art can rip your force shield in less than 5sec watch out for them. bazooka and any explode weapon can hit you if it near
-if you have sdc, you can find lone enemy, use shield, and stun them to death
-dont go near front line too much, dont try to guard/shielded everything. baltheon core isn't that good
