The mass murderer is rare these days but what do when you get i shall tell u
Step 1) when your a mass murderer never target yourself say X says he is gonna check you most people take that as a easy kill it is not a cue to target yourself you will get lynched no matter what.only ever target yourself night 1 when last wills are not made
step 2) listen in to what the town say so once again X says he is going to check Y but a doc will also be on him so you can spree at Y house getting 3 easy kills but remember town will never say this if mm is a fixed role so dont get your hopes up.
step 3) when claiming a role think out of the box of mm and veteran of course if vet is in play you can but i think these are a perfect example say you target Y and Y is gf you can say your invest/sheriff and get the gf killed earning the towns trust or claim surv and just survive but make sure there is a neut in play.
step 4) lastly a few heavy mm targets are night 1 spree at 1 house he is a big target and night 2 15/14 these are very big finally spammers and trollers spammers you will get a mother load of kills.
so there my 4 steps of a good mm if you find this useful in anyway or not useful reply and give me feedback.