what ADC/MID champion should i buy ?

Prolly cass or kalista are the best of those.

You didn't really give us a reason for the champions you chose.. if you want a mage what is it about xerath cass and viktor that appeal to you...Need an assassin, pick Talon, if you wana 1v5 penta pick cass if you want wave clear pick xerath if you want a lil more burst to your wave clear pick viktor... if you wanna lose games pick quinn.. and if you want to play OP shit pick kalista. Walaah make a decision.

First It depends on what your main role is: If your an ADC main then I'd go with Kalista but Quinn is fun as well. If your a mid main, Viktor is a lot of fun to play. Also want to account for your play style. Kalista is mobile ADC while pre-6 Quinn is not. When Quinn gets her ult she gains mobility with Valor. Quinn is also really fun in Top Lane and can pull off some real nice mid lane ganks from top lane.

Xerath has really stop poke due to his range but lacks mobility. Cass is a DOT style champion which is pretty fun, very similar everyone favorite Yordle . Talon is an assassin style champion that can really pack a punch with items. Viktor is really unique with his stages an evolution to his skills are you upgrade your hex core.

So its really about what you like. I recommend that you maybe watch a few videos of each champion an see which would suits your play style the most or which you would find more enjoyable. Good luck in your choice.

quinn is a lot more enjoyable since the bug fixes and the auto attack reset on her E. she's got a really strong solo lane and plays out like an assassin post-6, and her bot lane is quite good with a hard engage support.

Talon you need to understand your lane strengths of yourself and bot and top so you can get roam gold/advantages. Xerath you can wave clear/poke any lane where you can safely AA the enemy champ Quinn is a niche pick but extremely useful in her niche (aa reliant bruisers hate her mid game and plenty of roam potential with ult) Cass is almost always a skill match up in any lane she's in, it's hard for enemies to follow her on her roams in fear of bush ambush Kalista is pretty hard to use effectively and you need to understand what item will help you now in this game, (most champs benefit from this but kalista will be crippled if you, for instance, but hurricaan while behind)

TY all for this sugestions :D i will get cassiopeia :D it sounds pretty fun...and it's a nice apc late game :D x6 :P