Yeah, so like I said in an earlier post that no one cares about, I got Karma. Now I just need some help as to what i'm doing with her.
Runes and masteries for insert lane role here? Starting items for support Karma? Core items? Situational ones? Champs she synergizes well with? Champs to be wary of? Thanks.
I've enjoyed a lot of recent Karma Support.
She is hella fun. A few tips to playing her in support:
Q is a great poke with out without R. Safe R for when it counts or when you need to lay down some peel to escape.
W is really powerful early on but you will rarely find uses for it after laning phase except when chasing down stragglers of the enemy team when they lose a team fight. However, during laning phase only use it when you need to. Once you start throwing this out you will likely need E as well followed by a Q. Your mana will be gone really quick with that.
E + R is an amazing ability for saving someone from an assassin or any kind of burst. It isn't just a tool for giving speed boosts. When E is maxed with a couple ranks in R its like a Shen ult every 20 seconds.
I like to start with 
Items I like to prioritize are: 
and 
but I will occasionally rush other items like 
or 
if they are needed. I will often get 
. If I get a big lead I do get greedy and build AP items but these are my normal go to items.
For boots:
I build these when I have an ADC that can stay safe and I can roam for short jaunts.
Karma has a really strong early and early mid game so building these can really amplify that
More damage = more win! building these are pretty common because her shield already gives MS boost 
Karma is so versatile that there are not really any ADC she cannot help out or synergize with. She can max Q and be aggressive or E and be passive. She can struggle against hard engage types but if you save your E + R to save your ADC or yourself you should be fine to at least not die and be able to back to heal.
Long post!
If you've ever played Lulu support, Karma is fairly similar to that really.
You need to familiarize yourself with using mantra on each ability however. RQ is your best damage/poke spell with a strong slow zone, RW for a fairly strong heal and very long root duration and RE for engaging, disengaging or team-shielding something like a Viktor ult.
Karma is quite strong early on and she tends to fall off a bit later on, this is why I prefer to emphasize building AP/damage on her as that way she remains relevant for longer.
Runes: 9x Magic pen or Hybrid pen marks; 9x flat armour or health seals; for glyphs you can go Ap/scaling AP/magic resist, depending on your preference and the matchup; for Quints you'll want either AP, Flat armour or movespeed, again it's highly preference and matchup based.
Masteries: 9/0/21 or 0/9/21, the utility tree is too good for Karma not to take advantage of. You'll want the extra defence vs All-in lanes, the offensive against poking/ranged ap supports.
Starting items: Always Spellthief's Edge or Ancient Coin with either 4 Health Potions or 3 Health, 1 Mana, always take the warding totem for laning. Coin is great for lanes where you need sustain and when you plan on upgrading to Talisman of Ascension; otherwise go with Spellthief's edge and sell it later on.
Core items: Always take 
and 
.
Aside from that, it's up to you what to build. You will either want to build with an emphasis on AP or utility, or mix and match the two. AP support is all about improving your base abilities for some nice Q damage and big E shields. Pure support focuses on building utility items for your team largely to the detriment of your basic abilities.
When I play Karma I tend to mix and match utility and AP items based upon the situation. Magic Pen items like Void/Liandry/Sorcerer's shoes amp up your Q damage a lot without requiring much AP, so when you're mixing your build they're the items you'll want to look for to boost your damage.
Banner/Locket are great vs magic DMG, Ardent Censer is useful when you have either a full AD team or many auto attackers, Zeke's to snowball your ADC, Morello's for it's excellent and cheap stats, Rylai's gives your W a 40% slow so it's basically guaranteed to get the root off, Mikael's vs deadly CC (Annie, Lissandra, Veigar), Talisman for engage/disengage. I could go on. You really just build for what you and your team need, and build what's appropriate vs whatever you're facing.
Viable AP items: 
Viable utility items: 
A good mixed build: 
Karma is really a generalist when it comes to her role. She doesn't have specific synergy with certain ADCs and most of her matchups are fairly even. The only enemy supports I would be wary of are Leona/Nautilus. At level 6 they can probably 100-0 you with their ADCs if you get caught, as they can against any squishy ranged support.
