If Rumble's Tristy were in Mechwarrior/Battletech...
What weapons would you put onto it?
Try to keep it realistic. Nothing that would weigh more than... say, 75 tonnes. (Don't ask me for weapon weights, I'm not a Battletech expert.)
I'd give him some LRMs, an ERPPC or two, and maybe some Machine Guns for close-quarters (and for when overheating).
EDIT: On the note of Battletech, it's a shame Rumble's mech can't torso-twist very much.