Proletariat
Proletariat is a melee character with the ability to duplicate himself up to 6 times. He excels at damage mitigation, positioning enemies, and damage.
Damage Mitigation
Start Proletariat with Defensive Sacrifice and Shared Burden. Whenever he takes damage, if there is at least two damage and you don't successfully defend against it, forgo blocking the dice and duplicate or remove a duplicate. Try not to allow yourself to lose more than 2 health this way. When you start with at least 3 clones in a turn, swap Shared Burden for Overwhelm. Use Overwhelm to create 3 more clones and use Defensive Sacrifice to mitigate the big hits. If your health gets too low, consider spending a round with Regroup and Recover in place of Defensive Sacrifice. Just make sure you remove your most vulnerable clone(s) with the power. By the end of your second turn you should have at least 4 clones. Maybe more if you were attacked.
Positioning Enemies
All of Proletariat's attacks have "Push 1". This means any target he attacks that is in melee range, regardless of whether or not he hits, he gets to push one hex. Some great Positioning builds include Hammer Sweep and Overwhelm. With Hammer Sweep you can push all targets that are adjacent to any of your Proletariats. With Overwhelm you can reposition a target adjacent to each Proletariat. And, if you set up a chain of Proletariats, you can push a target down a line into and through hazard spaces. Remember that push is mandatory, so time your attacks appropriately! Sickle Formation is also great here as one sprint allows you to readjust all your Proletariats for whatever pushing shenanigans you want to use.
Damage Dealing:
Proletariat's base attack is 4 dice with two chances at missing. That means on average he will get 2 to 3 successes per attack. Add Overwhelm, multiple clones, and the fact that The People's Hammer is unlimited and you're looking at 8 attacks a turn at max. Hammer Swing can increase the number of targets hit. If you add Tactical Flanking to the mix, any attack done on a target adjacent to another Proletariat adds 2 more dice for 4 to 5 successes. This is Proletariat's attacks at their finest. Again, pushes are mandatory and all of Proletariat's attacks push. So, push in a sequence that will keep your target near the Proletariats you haven't attacked wit yet.
Solo Tricks
Before your first turn, I would start with Defensive Sacrifice and Shared Burden. At a minimum start with Shared Burden to mitigate attacks against Proletariat before his turn.
Sickle Formation and Overwhelm allow Proletariat's clones to cover a lot of distance fast or they can allow you to surround a target and hit them X times where X is the number of clones adjacent to the target.
Don't forget that you can duplicate to an adjacent hex regardless of elevation change. Duplication can also give you that one extra hex movement needed to get to a character.
If you're willing to take a bit of damage, you can use hazard spaces to generate more clones.
Shared Burden and Defensive Sacrifice make for great mine-sweeping when you're dealing with Ambuscade.
Spread out your clones to avoid area attacks and to allow you to reach opponents most anywhere on the map quickly.
Leave a clone someplace secluded and safe when you have Defensive Sacrifice to keep Proletariat nearly invincible. Ambuscade and Tachyon can both take out this lone clone quickly, though, so be careful.
Regroup and Recover + Overwhelm used by 2 clones out of at least 3 restores Proletariat to full health.
If you have at least 3 clones, Overwhelm allows you to restock to full clones with one action.
Team Tricks
Champion Bot with one Proletariat within 2 hexes gives all Proletariats +2 dice on attack rolls. Combine this with Tactical Flanking for +4 dice total on any attack on a target with at leat 2 Proletariats. Or use it for single 6 die attacks.
Foresight works on Proletariat as long as one Proletariat is close to Visionary. However, since Foresight is once per turn, it isn't a great turnaround.
I don't know if it is official or not, but if Legacy has line of sight to one Proletariat, he may be able to use Heroic Interception on a different Proletariat clone.
Beacon and Proletariat with Overwhelm allow all of Proletariat's clones to take an action.
Beacon with Bolstering Teamup and Proletariat allows you to get out 3 clones at least by the end of turn 1.
Proletariat can push enemies onto a tower of impaling structures created by Absolute Zero. This is very difficult to pull off, however.
Proletariat with Defensive Sacrifice and Ambuscade can set a pile of traps and then set them off. They can either push a target onto the traps and pop the clone or have the clone set them off itself and then pop.
The Operative can pull enemies to any location adjacent to her. So, surround a location and let the Operative pull an enemy into the center of an overwhelming number of clones.
Legacy's Motivational Charge can be used on Proletariat with Shared Burden to create a clone and heal all other allies at minimal health loss if Proletariat is not at full health.
Weaknesses and Enemies to Watch Out For
Each Proletariat is a target, so Proletariat is especially weak against area attacks. To reduce the risks, keep your clones spaced out at least one hex apart. Maintaining Defensive Sacrifice is also helpful here, as you can remove clones instead of taking damage, but it gets through your clone count quickly. Strong AoE attackers you should watch out for include Ra, Ambuscade, Bunker and Omnitron V.
Shared Burden forces you to duplicate. If you are forced to duplicate a seventh clone, Proletariat gets incapped. It is best to drop this ability once you have 3 or more clones.
Proletariat is a melee hero and does not have mobility. This makes elevation changes and movement slowing powers a weakness for him. Remember that cloning can be used to give you that extra hex you may need.
The People's Hammer has 2 miss dice. Anything that forces re-rolls of successes or adds more miss dice really hurt Proletariat. Watch out for Boar's Rage (?) from the Operative and Twist the Ether from Visionary. Don't attempt to take on Legacy without Tactical Flanking or lots of dice and an aimed shot if he has Danger Sense in play.
Opponents Proletariat is strong against:
Omnitron V: Omnitron V does not like Proletariat. First of all, Omnitron V is immune to pushing. That means Proletariat doesn't have to worry about pushing him out of range of attacks from his clones. Second, Omnitron V is really big. Proletariat doesn't have to keep his clones too close together when surrounding Omnitron V.
Ambuscade: Ambuscade has a ton of AoE, but a careful Proletariat won't send packs of clones at him. However, Ambuscade is also about ambushing a character and taking them down fast, or trapping characters in a minefield. With Defensive Sacrifice and Shared Burden, Proletariat can disarm mine fields or suffer an ambush and come out with more or less clones, as needed.
Bunker: Proletariat can shrug off an Omni-Cannon blast and can come out on top after a full Turret Mode assault from Bunker. If Bunker is in Turret Mode, Proletariat can surround him and take him down pretty quickly with Tactical Flanking.