Warning: If for whatever reason you have not yet played Borderlands 2, this contains spoilers for aspects of Gaige's character. It is also an analysis of a very complicated mind, so read with caution.
As a series, Borderlands has had a number of unique characters as far as attitude, art design, and general concept goes. However, while many of these characters have intriguing concepts, they rarely last long in my memories. I could tell you plenty about Zer0, as I already have. I could tell you how much fun Mordecai was in the first game. I could tell you how differently the playable Siren characters are in the first and second games.
I'm not going to, because while that could be fun, anyone could write it. That's not a bad thing, exactly, I just want to be very specific in how I tackle certain subjects right now.
For the moment, let's narrow our focus once again. Meet Borderlands 2's first DLC character, Gaige:
Gaige is a character that's hard to get a read on, psychologically, and that's why I like her. Her interest in SCIENCE! (capitals and punctuation necessary) is genuine and passionate, but her pet project is much less benevolent than, say, a baking soda volcano. In the context of Borderlands, a "Claptrap" was initially a mass-produced line of somewhat intelligent but very boxy and talkative robots. Gaige, naturally, decided that wasn't good enough. Meet Gaige's passion project, "Deathtrap":
Deathtrap, the origin in part of Gaige's pun-based class name, is anything but benevolent... At least, to those who are not its creator, or allied to its creator. As far as Gaige is concerned, Deathtrap is a symbol of her scientific progress, an indefinitely long experiment, and one of the closest things she has to a friend.
With the character of Zer0 there were plenty of small, jokey references to memes and other media that I ignored as irrelevant to his character. With Gaige, I can't dismiss the references or memes entirely. "20% cooler" and "The Stare" are both skills within Gaige's branching skill tree that directly reference the modern incarnation of My Little Pony, of all things, and those are only the two I explicitly remember. There are others I didn't recognize, but a fan wiki did, like "Potent as a Pony", which adds health to Gaige and Deathtrap as it is leveled (https://borderlands.fandom.com/wiki/Gaige/Skill_tree).
Why is all of that relevant, you may ask? I'll get to that. First, let's return to the well of quotations, though there is a semblance of order this time around.
Long story short, Deathtrap activates inadvertently, and Marcie is killed. Gaige, despite her panic and denial, manages to be optimistic about the situation in her own way. She wanted adventure and a chance to pursue the legendary vault, and though the reason was one she never wanted, her grim circumstances gave her the chance. ~Echo Log 4 (https://borderlands.fandom.com/wiki/Gaige/Quotes)
It is also difficult not to mention that Gaige is prone to power highs that unleash a god complex, through one of her skill lines that trades accuracy for power. It's not subtle, either, with direct reference to the "Alpha and Omega" boast in one of the later dialogue tiers. Naturally, she doesn't take losing this well. How much of this is due to Gaige's personality and how much is due to the drug-like effects of successfully using her Anarchy skill, I am uncertain of.
Now, where exactly do the cartoon horses fit in? That's simple enough. Gaige has a very child-like view of both the universe around her and her own responsibilities (or lack thereof, in her mind). Her highly anarchic political leanings, various undiagnosed neuroses, and desire for more adventure in life collided with familiarity towards a fictional, fairer world than the one she inhabited. Severe stress from many sources, those and more among them combined into the metaphorical straw that broke the camel's back. (No disrespect intended to anyone into MLP:FiM , as it's a decent show and I imagine most people who read this don't have cybernetic limbs or personal murder-bots... No disrespect intended for anarchists, for that matter.)
At least, all of that is my interpretation of Gaige. There are many more out there, and disagreeing with my interpretation is both expected and welcome. After all, every Borderlands protagonist has some sociopathic elements as a result of the kind of dark humor the series has integrated into its brand identity. If you look at Gaige and just see another class, or a character with less depth than I interpret, you are more than welcome to do so.
What is your take on the series' one and only Mechromancer? No matter how different it is, I'd be interested in hearing it.
Sources used, other than those already cited:
Gaige concept art created by Scott Kester, used for illustrative purposes only. All rights remain with their original parties.
Deathtrap concept art created by Lorin Wood, likewise.