Maid: Someone who repairs and maintains their aspect. It’s also a pun, as they are metaphorically (maybe literally for some aspects?) made of their aspect, which lets them lend their aspect to others when they need help. 

Rage: Insanity, chaos, destruction, obsession/conviction, and negative emotions with a huge focus on anger. Associated with physical strength, many rage classes would be brawlers in an rpg. They reach their full potential when pushed to their mental limit and/or under an extreme amount of stress.

This... is a funny one.

So, since Maid's are often "made" of their aspect, or at least seem like it, I imagine a Maid of Rage could be either a perfect embodiment of everything rage represents, or, they'd simply bring it out in everyone they talk to. Yes. They would indeed have the power of ragebaiting.

Half-jokes aside, a Maid of Rage's duty would essentially be to maintain productive anger and conviction in their party. If they do it well anyway. If they're a shitty person they'd be doing the same thing but to a detrimental effect, enraging the party to keep them from actually achieving anything.

They'd essentially be able to emotionally manipulate people but with a focus on negative emotions. They'd have a huge influence over the mental state of their party as maids focus on keeping their aspect under their control over anything else, like how a maid of a house keeps it under control.

Maids tend to be support rather than offense when it comes to fighting. They'd be able to help others unlock great strength by forcing them to reach their mental limit and become overwhelmed with adrenaline or temporary insanity, which can be pretty useful in a fight if it directly correlates to how powerful you are. In homestuck's case, it absolutely does, as rage seems to be tied very closely to physical strength.

Them being good with support doesn't mean they can't interact with the enemy though. If they drive an enemy so insane that they can't coordinate themselves properly, it can be easier to fight. So they'd essentially be able to give buffs to the party and debuffs to the enemies. Enraging an enemy might make them more physically powerful but it'd also make them far less likely to hit and much more susceptible to damage, and make them useless when it comes to commanding an army or allies.