I want a new champ and don't know how to buy. ROLES: Top: Xin, Nasus, Sion Mid: Ziggs, Kassadin, Annie Jungle: Yi (don't play jg that much) Support: Alistar, Soraka, Janna, Zilean Adc: Tristana (also dont play adc that much)
Well I'd recommend having 3 champions in every role. This is if you have to play a lane and they ban your pick. Example, If you got stuck jungling, I'd always ban Master Yi because broken reasons. So fill up those slots first. Second consider how you like to play. If you like to build damage, you'd go assassin champs, tanks would pick tanky champs, etc.
I don't know the other roles just support.
Janna is incredibly strong. I am 36-18 (66.7%) win rate with her in ranked this season. It really, really sucks that they nerfed the minimum range of her Q but she's still great. Just be advised that your role is primarily disengage, secondarily to help the adc win trades, and tertiarily to poke. Don't go balls deep, son.
I am not a fan of Alistar. I don't like his build path because basically you build hp to maximize his ult but that gimps you on getting the normal armor and mr paths of a tank support. So for Ali, instead of Frozen Heart you'd probably go Randuins, and instead of Aegis you'd get Spirit Visage. Selfish builds throw games.
Soraka is OP right now against certain bot lanes. Basically if the enemy picks a Soraka I'm going Sona and I'm going to wreck. But if the enemy is Soraka and I'm Leona or Nautilus, or Braum and they are a really good Soraka, laning phase is going to suck ass.
Zilean is apparently making a comeback. If you can land his combo stun you can get kills. He has disgusting poke.
If you want my honest opinion of the best support at the moment, it would be Braum. My ranked winrate with him is like 80% over 25 games or so. His passive is beyond broken.
Corki is probably a good back up adc for you (as he's less auto attack reliant than other adcs, so good for those who don't like the role ). Ezreal (similar) and graves (for assassin-like burst) are honorable mentions.
Practice xin jungle as a back up since you already like him. Nidalee may also suit your playstyle.
Mid: LeBlanc if kass is your favorite, viktor or cass if not.
Support: you like to heal and need another tank option = Taric
Top: i get the feeling you'd like cho'gath or maokai.
If you intend to play ranked, I'd encourage you to get a second adc and jungler. Especially adc - it seems to be really not popular right now (as an adc main i seem to get adc almost every game). Tristana isn't super popular, but she is a staple in the lcs (so world's may make her more popular) and you still need a pick for those rare games where she's picked/banned and you're stuck adc.
I'll try to give something for each role.
Top : Tahm Kench - Really like playing him in top lane. Matches up well against a lot of melee and farm decently. He's really good at aiding jungler ganks as well.
Jungle : Rek'Sai - I always like having a Rek'Sai on my team. That tremor sense is nice as the game goes along and her ganks are pretty good. Her ult is great for keeping your presence spread out across the map. ( I don't jungle, so I had to go with what I like on my team )
Mid : Vel'koz - If you like Ziggs, you may also enjoy Vel'Koz. He's a great poke mage and really rewards you for landing consecutive skillshots. I find him to be a lot of fun to play.
ADC : Ezreal - Since you don't play ADC much I think Ezreal might work well for you. He's pretty safe to play and has multiple build paths. He plays like an AD caster more than a standard ADC.
Support : Nautilus / Thresh - Nautilus is a beefy guy with a ton of CC and initiation. He also works well if you want to play defensively too. Thresh is just an all around solid pick. Fits into most comps and is satisfying to play.
I have to agree with another post though, take your Xin to the jungle as well if you already like him. Same goes for Annie, but with support.
I'm not the best for jungle advice, but I think Vi, Udyr, or Pantheon are good options.
Out of the ones you listed Zilean is weird and not played very often. Its not that he's bad its just that he is outclassed by pretty much everyone whether he goes mid or he goes bot lane support. Although he is quite annoying if he has a Tryndamere on his team. Kassadin is very weak right now. He's due for a buff but Riot is reluctant to buff anything that is an assassin right now. Annie is super easy and at 450 IP you can't regret buying her even if you never play her. She gets a lot of hate because of how stupid and overpowered her kit is. Janna is wonderful and one of my better supports. If you play the support role passively you will take an immediate liking to her. She is known as the Queen of peeling because nobody peels better than her. Alistar is the king of peeling, but Janna is more effective at it. But Alistar can actually initiate a fight much easier than Janna can. Alistar is also much tankier and is useful for when your team lacks a tank. Soraka is the most passive support around. She stays all the way in the back and spams heals and occasionally pokes with her starcall. She's boring but if your carries are good at what they do she can make laning oppressive for the other team. Tristana is really safe. Long range, self peeling ultimate, mobility. Her waveclear is meh but her biggest flaw is her attack speed. Early on it is stupidly slow. Nasus is if you don't mind farming for the first 20 minutes of the game. If you can manage that his late game is sheer terror. Expect to be camped by the enemy jungler which sucks for you but is great for your bot lane. Xin is a great duelist and is very disruptive in team fights. He works great in conjunction with assassins because he disrupts the enemy team so well. Sion in the right hands is outstanding. His ultimate cannot be interrupted and is great at initiating a fight. If you know how to make use of his passive you can usually take 1-2 people down with you. And he works even better if someone is behind him healing him the whole time he is taking all the punishment the enemy team can dish out. Ziggs is fun. I'm not that great with him but he's pretty good at poking and objective control. His ultimate can farm mass minion waves so that allows him to roam freely without risk. Master Yi is a carry jungler. At 450 IP he's another one you can't regret buying. He's great at back dooring turrets too and mopping up any fleeing enemies. The trick is timing his Q to dodge enemy skill shots. Once you get that down you have pretty much mastered the hardest concept of his kit.
buy nocturne than eternum nocturne. Ulting with him is the best feeling ever
Jungle: Warwick, Udyr, Nunu, Olaf These are some of my favorite junglers and they are pretty easy to pick up with a little practice and possibly custom runes. Adc: Ezreal, Sivir, Ashe Ezreal is my go to adc since I do not enjoy playing the role as much as some others would, so playing him makes it feel like more of just playing a caster instead of a marksmen. Also Sivir and Ashe are really cheap and are great for chasing because of their ults. Honorable mentions: Volibear top, Malzahar mid, Braum or Tahm Kench support.
