卡尔玛的Inner Flame grants ability power corresponding to her percentage of missing health. This makes her deceptively powerful when baiting enemies, as your abilities will be much stronger than anticipated when near death.
Karma is an assault support, similar to Lux or Kayle , and requires feed. She needs to stay near the front line to use her abilities and harvest gold, rather than holding back like Sona or Janna and allowing her laning partner to take all the minion kills and do most of the damage.
In order to play Karma effectively, you must know when to use a Mantra charge.
Using Mantra on Heavenly Wave should be mainly be used during large teamfights. Because it is an AoE heal, it is more effective on multiple targets than self-healing.
Using Mantra on Spirit Bond can be used to help an ally escape enemies or cripple a fleeing enemy.
A risky, but effective, strategy is to use Spirit Bond on a champion that can rush into the enemy team and cause them to hit the tether (e.g. Rammus).
Using Mantra on Soul Shield is useful when going 1v1 or shielding an ally surrounded by enemies. It is the most damaging of her abilities. Use it on minions if a teammate is not present to deny last hits and provide ranged damage. Do not neglect the shield portion of this ability, as this is not a reliable harrass method due to requiring two cooldowns to clear.
Karma can act as a pusher by constantly healing herself, her allies and her minions by using Mantra in conjunction with Heavenly Wave.
When attacking a turret, placing Soul Shield on a siege minion will greatly increase the amount of attacks you can get in due to the reduced damage they take from turrets increasing the effectiveness of the shield.
Making the proper decision on which champion to Spirit Bond in a team fight or chase can be difficult.
When possible, it's normally a good idea to bond your initiator, unless he's not going to stay within the leash range for very long. In any case, is easier to cast Spirit Bond on the portrait on the left.
Aiming for a distant enemy makes it possible to catch multiple other enemies in Spirit Bond's beam, but will also make the bond easier to break with distance. Aiming for a nearby enemy should keep the bond intact and slow the pursuer most likely to catch you, but will likely not hit any other enemies.
Spirit Bond deals no damage to the bonded enemy, only enemies which intersect the beam. Consider this fact when under an enemy turret as it can be useful when pushing against their turret, since it doesn't draw aggro, and gives you time to run if the bonded enemy approaches you.
Because of the damage component of Spirit Bond's beam, it can be used to farm minions or kill neutral monster camps when you are outside of battle.
If your team has champions that can blink to the enemies like Xin Zhao or Irelia. Ask them to wait for your Spirit Bond before blink, since blinking with Spirit Bond instantly deals damage to the targetted enemy champion and also slow them. Twice the effectiveness while Mantra is on.
Soul Shield's long range and its Mantra-activated large AoE damage make it a great skill to max out first. Using it on yourself or an ally / minion (especially a melee ally or siege minion) can help absorb large amounts of damage and allow you to safely deal damage if used with a Mantra.
In the chaos of a team battle, aiming a specific ally can be difficult, so it would be a good idea to cast Soul Shield's on the portraits on the left
Karma always respawns with both of her Mantra charges, so using one with Spirit Bond on an ally or spawning minion will help get you back to the action quickly. With some cooldown reduction, the time it takes to get there may be long enough to get your second Mantra back.
By pressing the Mantra hotkey twice, Mantra will queue up on your next two spells cast.
The cooldown on Mantra starts when you press the activate it, not when the enhanced spell is cast. Activate Mantra well in advance of an imminent fight to get your Mantra back a few seconds after the fight starts.
At present, Karma is a relatively underplayed Champion, so it is not uncommon for both opponents and allies to be unaware of how her abilities work. Use this to your advantage.
However, even if the enemy team has no idea how Karma works, you won't be as good without a good team that knows how Karma works and take advantage of what you can offer. Such as run over the enemies while Spirit Bond to slow them down when chasing, or stick together so you can mantra heal your whole team.
Having defensive summoner spells and points in the Defense Mastery Tree is a good way to make the enemy underestimate your survival skills.
Karma's abilities can make her deceptively tanky. However since this tankiness comes from active abilities she is especially vulnerable while stunned or silenced, making Mercury's Treads OR Eleisa's Miracle, and Banshee's Veil good options when the other team has a lot of CC. Keep in mind that Tenacity doesn't stack.
Since Karma gains significant bonus AP from Inner Flame when she is at low health, the active effect of Zhonya's Hourglass may preserve her just long enough to allow her to use her abilities again while they are most potent.
Any Glass cannon build is more viable on Karma due to the fact that it makes her shield very strong and her aoe heal very strong. This makes her amazing in team fights and surprisingly tanky and allows her to bait people with Mantras + Soul Shield and Heavenly Wave much more succesfully.