Lilyncookies' only appearance in SMG4's videos was just a cameo in the first Ssenmodnar episode. I thinks this character needs more developpment, and also because I like her, I'd like her to reappear in SMG4's bloopers. And SMG4 insulted her by screaming she was ugly in Ssenmodnar 1, so I thinks he needs to apologize for that, although it's now very late; then I suggest a blooper made as a sorry to Lily in which she tries to defeat SMG4 after he insulted her. Yes I know, this plot would be similar to Birthday Freakout's.
Well, I don't exactly know which should be the events of the video, SMG4 himself (of course) would decide most of them. I think Lily would first see Bowser and ask him for helping her in her revenge, but Bowser would refuses because he'd be busy at that moment (so Lily would steal his cookies if he have some). She'd then go away and search for someone else. During her quest, she'd maybe steal (or at least try to steal) some cookies from several people (possibly including Enzo, some random guys, and Toad: that'd lead to a conflict or a fight with the latter) (I know stealing would make a similarity with The Bowser That Stole Christmas). She'd then later (somehow) meet SMG3 and somehow know that himself too is against SMG4, so they'd stand up together to defeat him. Later, when SMG4 sees and recognizes Lily, he'd remember the event of Ssenmodnar 1 and then hide in a bin as he once used to say he'd to do so in the description of that video. I don't know what would happen after that, they'd may try some attempts, SMG4 himself would decide.
About the characters, MM54321 would appear. OK, it's probably be a few minor appearances, bu I thinks he needs to appear, because he's a good friend of Lily, and they appeared together in Ssenmodnar 1. Starman3 would very probably appear too, but there again, he'd probably plays a minor role. One or several Police officier(s) would may appear too.
I'm sorry, but I need to go to bed, so I'll continue the next day.