My first was Pakfront, an AR/EM/Mun Blaster; that's her in my icon. Her costume designs evolved as more 'tech' armor pieces were added to the game, culminating in one that was mostly the Mecha set. As soon as power customization was available, I switched from the 'dial-a-gun' to the long-barrel sniper rifle, and from there to the Vanguard Redding Rifle as soon as I unlocked it, and have stuck with that since then.
Over the years, I worked on tricking out the character as an attempt to prove Statesman's claim that 'Range is a Blaster's defense', and with Boost Range and the various range bonuses from IO sets, I wound up with an entertaining playstyle; Full Auto had a range comparable to an out-of-the-box snipe and Flamethrower was close. It made leveling interesting in Peregrine Island, back when you would routinely see ten- or twelve-mob spawns of Nemesis -- she could run up to the spawn with Stealth on, hit Boost Range, Build Up, uncork Full Auto, then Flamethrower to crisp up the survivors... and then Rest to recover the roughly half her HP she'd lose from return fire while she was standing there. Playing Snipe Warrior was entertaining, too; with Boost Range, it was possible to snipe a mob and have them just stand there wondering why they were bleeding; it wasn't until the second shot that they would take off running as the server tried to find a path to get them in range of me -- or, more often, just trying to run away.
She was the character I chose to close the game out on, joining my fellow Guardianites on a Rikti mothershpi raid, not letting the pronouncement stop us from continuing to fight as if the game was going to continue forever; she was standing in the center of the bowl spraying fire at the rim when the game locked up at shutdown (too many effects going on for a genteel 'disconnected from server'). I have a screenshot that is timestamped a second after midnight, and it's hard to make out anyone under the glare of power effects.
