Advice one what champion to main top/mid
I've been attempting to scale up in ranked with little to no success. At the moment my go to champs are Varus/Karma. While my win-rate with Karma isn't awful, I find her to be extremely boring. I play her top/mid/supp. Taking Karma top gets a lot of raised eyebrows though. Varus on the other hand is extremely fun to play but I suck with him. I win lane by out farming my opponent for the most part but when it breaks down to team fights I get picked off too easily. Unless I'm completely in sync with my team, I'll just become a liability towards mid/late game.
Here is where you guys come in. I've decided to put Varus on the bench, he can come out for normals. I suppose what I need now is a champion that I can take top/mid and potentially carry with. My thoughts would be either Nasus/Olaf/Voli/Renekton for top, and Zed/Talon/Veigar for mid.
I've gone with these champions because from my failed matches I've noticed that my weakness comes from my inability to position properly. I have a tendency to end up cut off from my team. The way I see it is... If I'm going to continuously put myself in danger like this I might as well play a champion who can make a play out of it. Thus, the tanks and assassins come into play.
So guys, which of these champions if any would you consider to be the best bet for climbing the ranked ladder? Would I be better of just picking one lane and one champion to master? How would you suggest I improve my capability as an adc? It feels horrible to let my team down as soon as we hit the mid/late game.
At the moment I'm sitting at Bronze IV. While I feel like I have the potential to climb, with my performance thus far, I feel like I've earned my spot in the lower rungs of League quite fairly.

because hes fun


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Can play him top and mid or jungle, always "relatively" meta. Strong lane phase, good team fight, can split push. Itemization can vary based on being ahead or behind. Just focus on champs that can play both top and mid. Diana and Ekko are options too.
. Anyone with great range or waveclear.
at level 9 and if you're unsure about a certain bush, use that to check it instead of face checking.
respect his zone. Don't do stupid things for the chance to maybe get a kill. Don't push by yourself without vision. Play smart and you will improve. The more times you die, the more powerful you make the enemy team, the less time you spend out on the rift farming. Your team mate is stupidly face checking the enemy jungle with 3 are MIA, DON'T FOLLOW HIM. Your support gets caught by 3 when you guys are roaming, LEAVE HIM TO DIE. If you can keep your deaths under 4-5 in a game, you'll see a significant improvement in your performance. It's all about knowing exactly how much damage you can do without putting yourself in a position to get CC'd or jumped on.
kennen?