DISCLAIMER: this build has a lot of stripped armor (almost no head armor, at least -20 armor for each leg and arm) and it has not been tested (at least not yet, I don't even own this mech)... So this build is not for the faint of heart, but for the bravest men. _ Good to very good weapon synergy, 3 alpha coefficient (3 alpha strikes before overheating), good speed, excellent alpha strike damage (96.6), but low armor and slow cooling. Best used as a one time rammer (alpha strike the first one or two unlucky guys in front of you, then move back to cover... DO NOT attempt to perform a prolonged brawl with this mech like you would with a 4xLBX10 build or similar) or as a rear deterrent for nascaring opponents: nobody wants to take a full 96 damage alpha strike in the face and whoever gets it, I bet my ass he will move back to cover if he is not backed up by the rest of the nascar.
I'm not fond of that STD engine: this mech can't zombie, you are not constrained to use a STD engine (i.e. it isn't fitting an LBX20) and being slower in a brawler is generally a bad idea... If you are willing to lose a DHS while fitting some additional armor, you can downgrade to a sligthly lower LE320 and free 2 tons to play with: at least it will still retain 20+ alpha strike ammo. Also, Fafnir's arm are really small and the chances to use them as shields are very slim, so that's why you can almost safely strip armor from them. Or you can downgrade 2xML to 2xERSL, achieve a similar performance and add 1 ton of armor _