Man, all of these abilities all sound super cool, and I absolutely love the theme of darkness and and your unique take on already well-established Valorant agent abilities, but I do see a few problems with your current design. I think the passive ability is a bit too Op, because being able to passively increase weapon damage in fights when you're being fired upon can really give the player an unfair edge. 20% is a lot (depending on the weapon), and using this agent, you can for instance, one-tap someone with a phantom while the ability's active, which would reduce the effectiveness of the vandal, and such an increase to all weapons would likely break the game, since the damage output of each of these guns is very-carefully balanced and calibrated. Also, I think the ult is a little weak, since 118 damage might not kill any enemies who even bought a light shield, so I would increase the damage, even if this is mainly a mobility ult.
Another huge issue I have with this agent is the ability Shadow form, which I think is way too overpowered, because the invincibility would basically let you get a free plant, which also lasts 4 seconds, or even a free half-defuse, which is 3.5 seconds, and would also let you basically win any firefight because you literally can't die. One way to make this ability more balanced is to not let the player perform any actions such as shooting guns/stabbing or planting/defusing when this ability is active, or have these actions end it prematurely, making it into more of a stealth ability for info/positioning, rather than as a more offensive/combat-oriented ability. But that still wouldn't stop people from using it as a meatshield for their teammates/baiting shots without risk without any real counterplay against it. Other than that, I would love to see Erebus in the game, and I think it's kinda funny that you decided to put a literal Greek god into Valorant, but honestly (though I really wanna know the backstory to how this even happened), I think it fits the game quite well.
