Mel simply keeps doing councilor shit. Without Noxus breathing down her neck, she probably has a smoother time of things than in canon.
[GOOD END]
The other councilors don't get blown up by Jinx.
[GOOD END]
Without shimmer on his side for both revenue and as a weapon, Silco is stuck in endless chembaron turf wars and unable to achieve supremacy.
[BAD END]
Sevika spends the rest of her life as hired muscle/true believer for Silco's cause until inevitably she gets careless enough, unlucky enough, slow enough or old enough that she loses fights instead of wins them and bleeds out in an alley somewhere.
[BAD END]
Without Silco achieving supremacy and looking to consolidate his grasp over the entire undercity, Vander continues to run the Last Drop as its proprietor and an unofficial lawgiver to his little corner of Zaun. His topside connections and natural brawn and charisma help him live decently long and healthy by Zaunite standards, and he probably actually gets to live to see the 4 kids grow to adulthood.
[GOOD END]
Milo and Claggor, assuming they don't slip and fall to their deaths or die in any of the millions of ways ordinary life in Zaun can kill you, grow to adulthood. Probably get jobs and girlfriends or something.
[GOOD END]
Vi takes up professional boxing and most likely enters some underground competitions and fighting championships. She has inexplicable tard strength even without the hextech gauntlets so does decently well. The head trauma builds up over time though and she can't form complete sentences without slurring her words by the time she's 40. Which is above the average Zaun life expectancy anyway
[ACCEPTABLE END?]
Jinx doesn't blow up her family and go full schizo as a result. Powder will be a slightly off-her-rocker mechanic who does odd jobs fixing shit. Builds wacky machines in her spare time, but only as a hobby.
[GOOD END]
Benzo doesn't get killed, runs his store until obesity and heart failure kills him.
[GOOD END]