The skins we have for him however, include a soccer team, a thief, a robot, and a.................Sweetheart skin.
First of all, skins aren't necessarily meant to be taken wholly seriously, especially world event/holiday skins like Striker or Heartseeker. Skins are, more or less, intended to be an exploration of a character in a different theme or framing - most frequently the theme. (I'll get to that in a minute)
Second...
...Thief...?
Tell me exactly how Hired Gun Lucian looks like a thief. I can't speak exactly to what the thematic is behind Hired Gun, but, it's certainly not a thief thing. It's more of a "mercenary" thematic than anything else.
So, thematic. Skins give a picture of a Champion in various different thematics that may otherwise be alien to them. Such as Arclight painting otherwise dark, violent, and brooding antiheroes (barring Vel'Koz) into transcendent divinities of retribution, or PROJECT: giving Champions a futuristic revival in carbon fiber and neon.
Very rarely will skins re-tread a thematic for a given Champion, if ever. Few rare examples do exist (Officer VI, Officer Caitlyn, Freljord Ashe, Ionia Master Yi...), but, for the most part, skins try to contextualize Champions in new, different settings with new, different personal thematics, without contrasting too harshly with their current ones.
For example, Blood Moon Jhin takes the meticulous assassin and places him in the Cult of the Blood Moon, being a priest of sorts, who remembers the rites of the demon masks in exacting detail. PROJECT: skins take Champions and their core identities, and redefine them as futuristic super-soldiers. Some may break their coding constraints (Ashe, Vayne, Jhin), and some may remain as part of PROJECT's design (Zed).
Then, of course, there are thematics that enhance a Champion's core thematic, such as Dark Star Thresh. Thresh is horrifying, inescapable, he is a spectre of dread and terror who stalks and torments his victims.
And what greater example of inescapable dread could there be than cosmic nihilism? The all-consuming hunger of a black hole, collapsing and dragging everything with it.
So, yeah - skins for Champions should in general not be redundant. They could be extensions or reinterpretations of their core thematic, or enhancements, but, if you want the Champion's core thematic - you just use Classic.
Besides, if you really want to imagine yourself as Dante from DMC, just get the Lucian Noble Chroma and run with the red palette.