You want to get an all Maliwan Hide 55k roid, and and all Maliwan Love Thumper 39k. You want to get a Slag Rapier, preferably with Vladof grip and + fire rate You will also want a Slag Evisceration Rubi You'll need a good RL, too. And something else to round it out.
There is the MoS relic now that adds 35% melee, but I prefer the Vitality Relic The Legendary Hunter Mod is good for a bloodshed build, and it's what I'd recommend. I also think the Longbow Quasar is the best grenade for a melee zero.
How does this build work for bosses? I am just curious since I just started a new assassin. it looks cool but not sure how well it works with Warrior/Bunker/Pete, etc.
You can melee the warriors feet, pete can be killed faster with backstab. When he does his nova blast you can get 5 or more hits without a problem. And as for the bunker...I couldn't get a single melee in. This guy on the other hand. Go to 6:30 for the bunker fight.