Seems kinda vague, since some champs are wildly different in difficulty while fitting the same role. ESPECALLY mages, since they vary so much. Annie is almost all point and click, while someone like Lux is all skillshots. Then you have "mages" like Heimer who can put down turrets and afk, and others like Syndra or Cass who have to micromanage their powers.
I'd say it's CHAMPIONS who bring out the delusion in people. Champions who bring out the most delusion and "Omg, I'm awesome" in people DO tend to fit a theme though.
,
,
,
,
,
,
,
,
,
,
, 
These champs are all pretty regularly called out for their players being kinda jerks. Some are bruisers. Some are assassins. Some mid, some top and some jungle. What most of the have in common is that they pubstomp. They are either very easy to use and do well with, or are champions that newer or inexperienced players have difficulty playing against. Many are snowbally or can hard carry a game if they get a lead, and most promote the kind of #yoloswag all-in-all-day kind of playstyle that appeals to aggressive players. Not shockingly, aggressive players are often hot-headed players, and since many of these champs are prone to falling VERY far into uselessness if they DON'T get ahead and start snowballing... they often dive in hard, fail and immediately get salty over it. To add fuel to the fire, since these champs are VERY stompy when ahead, they see their wins as excuses that they're awesome as heck. They went 15/6 with Riven last game... they're freaking FAKER! Nevermind that Riven snowballs like a mofo, so they pretty much just got ahead and steamrolled by facerolling the keys. To them, this is concrete proof that they are Diamond material and it MUST be their team holding them back in games they feed. Not that they tower dove Nasus three times in lane and died each time to withering without getting a kill. The damned jungler should have ganked! EASY KILL!
So yeah... I don't think delusion is about the role... I think it's about the champ. With the infamous pubstomp champs and anyone whom the meta considers "free win" to be top of the chart in terms of how smug the player will be if winning and how deluded and blame-happy he will be when losing. That kind of player is attracted to the champs they feel are the "best" and "strongest" and they will assume that first time Jax or not, this assures them a win against that silly Trundle player who has 100+ games played on him. I mean... it's a counter, right? Surely that guy has never learned how to play against a counter! Now time to tower-dive his... OMFG TRUNDLE IS SO CHEAP FREAKING PILLAR OMFG IM DONE WITH THIS GAME!