Can do!

What part of the wasteland does Elliot hate? Probably the post Fallout 3 Capitol Wasteland. Imagine spending nearly two years trekking from the post New Vegas Mojave, across the Mississippi at the delta, and up through Appalachia only to learn from former resident ghouls that the Capitol is now shoot-on-sight to anything even mutant-adjacent. Then spending several months witnessing it firsthand.

Art by the amazing @nereeitor

Elliot's not exactly an OC, considering he's a named recruitable character in Tactics, but he has about as many unique lines as Charon.

He was the de-facto leader of Ghoultown in Quincy. When the Beastlords (a cannibal cult with a mutation allowing them to telepathically control animals) raided the town and took both humans and ghouls hostage, the Warrior (the player character for Tactics) and their Brotherhood team rescued the hostages and defeated the Beastlords. If the Warrior saves his brother Gorgi, Elliot joins the Brotherhood.

(Side note: this is the Midwestern/Chicago Brotherhood of Steel that Bethesda reconned out of existence for being too different. I'm guessing because they were do-gooders who counted ghouls, robots, super mutants, and even deathclaws in their ranks, instead of being paranoid techno-fascists. But I digress.)

I've always pictured Elliot as a pre-war punk because of his post-recruitment portrait with all the piercings. I imagine him raising hell and protesting the war. After the bombs, he became a crucial part of Ghoultown, maybe not founding it, but helping keep it together.

Arlene and Evita used to sneak over to Ghoultown to play until Evita's mom (the town mayor and Arlene's adopted mom) had a fit. I can picture Evita sneaking over to Ghoultown and becoming friends with the other ghouls, including Elliot.

Once Elliot leaves for the BoS bunker, he holds his own as a tactician. He can shoot, but he's far more useful as a lock picker and logistician. His height keeps him from specialized duty--he's almost two meters tall.

When Quincy gets nuked, he gets special leave to stay in town and rebuild. (Canon divergence. In Tactics, the PC takes a live nuke from the ruins of Kansas City and uses it to blow open Vault 0. In my version of events, the big bads from the setting follow the PC and set off the bunker buster in Quincy.) The only human survivors of the blast are turned into ghouls. The place becomes The Hub but for radiation-resistant folk.