Personally my issue with that sort of thing is that I know, at an equal skill level, things like that would so easily be punished or exploited that it's not worth trying. That Warwick didn't have Smite so he was going around lower than he could have been, and as such getting killed; that could have easily been the other way around considering his sustain exists at all versus Cassiopeia who can only get hers through items. And I'll give you how far ahead you obviously were (because of one of the aforementioned "off-meta" picks (not to mention one that left the game at some point)) but that still could have been better used and were I in a more sentimental mood I would call it disrespectful to the other team in the sense that you're basically saying "I'm so far ahead I don't even need IE or GA I'm getting like a hundred more damage on my ult and almost nothing worth mentioning on my W instead of cementing my lead for sure." Of course, if as you say, everyone was chill about it afterwards or in general, that's cool and more power to all of you.
The way I see it is that "off-meta" should refer to champions being played normally but in another position- if you've played 500 games with LeBlanc and decide "yolo I'm taking her bot lane to ruin some carry's day" that's whatever if you build her as you would anyway and either-
compensate for lack of your own carry and end the game with a surrender at 20 or otherwise extremely quickly
put your carry elsewhere, say, Quinn top or Sivir mid
If you don't, any organized team will plan against that and beat you eventually or exploit whatever weakness you've stuck yourself with in general.
In a similar vein, there's the whole lane-swapping thing- if the opposing mid is someone you're concerned about, or you picked yours first and then they grabbed Kassadin or something, put your duo lane mid and ruin his day or force 1v2 lanes elsewhere to push a turret and alleviate an enemy advantage. That's also non-meta because the meta is currently defined as solo top, solo mid, jungle, and duo bot. If you want two mages bot and a carry solo lane man you do your thing so long as you've got a plan for if it doesn't work out as... well, planned.
On the flip side and things I would consider essentially trolling, please do not play cassiopeia adc, or sion support, or jarvan support, annie/karthus/ezreal jungle (trust me, i speak from experience on every single one of those examples) or any of that unless your whole team is aware and doesn't mind, or you have some overwhelming advantage from the get go, be it in terms of skill or otherwise. And don't get me wrong, I've played with things like Vayne with support Anivia and actually that might have been my best Vayne game (not that there's many to compare it to) so you can ditch that relatively unnecessary "meta sheep" comment there because they've done worse things than that and won games with it. I've seen an AD Gragas from Tony, an AD (spell vamp??) Ahri from Inuki, and Vega with "support" Udyr whose end build was 3x BT, IE, boots2 and Sword of the Divine and he had the most kills in the game. That doesn't mean I'd readily hop on the bandwagon in champion select with four strangers I've never seen before, but maybe that's just because I don't know how to have fun and LoL is a very serious game. Enough reason for you, Roo? In any case, because this is the screenshot thread and not "Ikaru goes on a rant about things that bother him" here's a quinn screenshot from LoLking
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