Older champions are more likely to get reworked because their kits are more one-dimensional and Riot is trying to move away from that.
I know. All the champions and their kits exist within the one dimension that is Runeterra.
Ugg. I want to get my placement games in ranked out of the way, but I've been having some really horrible luck these past few games. Had one where we had a HORRIBLE jungler who wound up going around feeding every lane. Then I wound up in a game with that same jungler again, but to top it off, we had a troll on our team as well. Didn't even matter that I was 7/1/0 as Kog'maw when you have someone feeding a Talon who can then just dive in and one shot me every team fight. I swear I'm going to wind up in bronze because of stuff like this. 
You should have dodged when you saw Orianna go top lane against a Sion or you should have picked an ADC that can self-peel for themselves. As Kog'Maw what are you going to do against a Sion + Volibear front line with follow-up from a Sona, Ashe, and Talon? Talon has so much lee way to wreck people in team fights with having a hard engage front line and three follow up stuns.
No one on your team bothered to buy a pink or had oracle despite him getting the most kills on the enemy team (in order to reveal him when he uses his ultimate). No one on your team bothered to buy Mercury Treads instead opting for mobility boots, sorc shoes, and battle greaves. Orianna and Blitz were the only ones who bought armor when the kill potential was all AD i.e. Talon, Sion, and Ashe.
The fact that you were dealing with a bad jungler from last game should have given you even more reason to have dodged the game. You can dodge your first ten promotional games with there likely being some passive -3 LP loss (which is nothing compared to actually losing a game which can be -15 ~ -20 LP) and no change to your match making rating.
You picked Kog'Maw with a really bad comp against an enemy team that had a really solid team fighting comp. The fact that you had the second highest amount of deaths on your team shows that your team couldn't peel for you and opted to run away. Yasuo fed, but someone should have told him to build bruiser so he wouldn't be useless because at that point he's not doing anything for the team with his current build since he obviously can't play to the meta so why bother, have him get tankier so he can last longer with his stupid play.
It's a pretty unfair system to be honest. Not just because of the fact that your placements are dependent on the ability of at least 40 other people if you don't duo (that's not including your opponents). Not just because of the feeders, afks and trolls. But because those games have so much more weight than any other games, so your overall luck is arbitrarily magnified by whatever luck you get in your provs. So if you're like me and had 7/10 games where you had afks/trolls/feeders, that means your luck was really bad because those games affect so much.
I'm punished harder for having those bad games in my provs, rather than say, when I climb a division and have the grace period at 0 LP, or in a promo that I still end up winning. You can't really say 'just carry through the bad luck'. You'll generally be placed in Silver elo for your provs, so if you're a Bronze-Gold level player, then you shouldn't expected to hard carry through bad luck in the elo that you deserve to be in. That's basically like telling a Diamond player 'if you deserve to be Diamond you should be able to carry 4v5s and games where your lanes have fed 3 kills each in Diamond'.
The system is fair because it's a system. It can't discriminate and intentionally put you with feeders. You may be placed with them in a bad spat of games, however everyone has an equal chance of an event like that occurring. It's precisely because those ten games matter the most that you should think about doing things like joining in a duo and by not taking advantage of that you indicate that you are not taking every measure possible in order to win. You play ranked casually, so you ultimately ended up with your main getting a casual rating. If you want to play Zed in mid-lane then you can guarantee a 100% chance of doing so by being the captain of a Team Builder game. Your match history indicates that you binge on ranked games playing several in one sitting, even if you end up losing three games in a row.
Sinister Slush
: Twitch is one of those characters I'd want to be good with but always end up feeding uncontrollably instead.
