The only place to could find the particulars for BG medals was in the in game help menu. I've basically just copy pasted it here so that you can see from where your points are coming.

Deathmatch
Bruiser: Deal at least 5k damage 50 points
Fearsome fighter: Deal at least 25k damage 100 points
Gladiator: Deal at least 50k damage 200 points
Champion: Deal at least 500k damage 400 points
Heavy Hitter: Score a 10k damage hit (repeatable)
Crushing blow: Score a 11.75k damage hit (repeatable)
Minor mender: Heal for at least 5k damage 50 points
Heroic healer: Heal for at least 25k damage 100 points
Medic: Heal for at least 50k damage 200 points
Fearless physician: Heal for at least 375k damage
Critical heal: Score a 7.5k healing hit (repeatable)
Rapid recovery: Score a 15k healing hit (repeatable)
Assist: Help a team mate kill an enemy player (repeatable) 100 points
First strike: Earn the 1st killing blow 111 points
Killing blow: Earn a killing blow (repeatable) 100 points
Double Kill: Kill a within 10 seconds of a prior kill (repeatable) 222 points
Triple kill: Kill a player within 10 seconds of earning a double kill (repeatable)
Quadruple kill: Kill a player within 10 seconds of earning a triple kill (repeatable)

Capture the Relic
First relic: Capture the first relic of the match 111points
Relic runner: Capture a relic (repeatable) 500 points
Relic hunter: Kill a relic carrier (repeatable) 100 points
Relic bruiser: Deal 5k damage to a relic carrier 50 points
Relic fearsome fighter: Deal 25k damage to a relic carriers 100 points
Relic gladiator: Deal 50k damage to relic carriers 200 points
Relic champion: Deal 375k damage to a relic carriers
Relic crushing blow: Score an 11.75k damage hit to a relic carrier (repeatable)
Humble protection: Do 5k healing on a relic carrier 100 points
Devoted protection: Do 7.5 healing on a relic carrier
Relic protector: Do 37.5k healing on a relic carrier
Divine guardian: Do 375k healing on relic carriers
Critical healer: Score a 7.5k healing hit on a relic carrier (repeatable)
Assist: Help a team mate kill a relic carrier (repeatable) 100 points

Domination / Crazy Kings (Have the same medals)
Vigilant defender: Earn 500 defence points at a capture point (repeatable) 1000 points
Offensive execution: Kill a defender at a capture point (repeatable) 10 points
Defensive execution: Kill an attacker while defending a capture point (repeatable) 5 points
Gleaming guardian: Take 15k damage 50 points
Dauntless defender: Take 30k damage 100 points
Valiant Vanguard: Take 60k damage 200 points
Steady Centurion: Take 250k damage 400 points
Iron Soul: Survive a 10k damage hit (repeatable)
Steel skin: Survive an 11.75k damage hit (repeatable)
Dominator: Capture a capture point (repeatable) 100 points
Helping hand: Score a 10k healing hit on an ally defender
Humble protector: Do 5k healing while defending a capture point 100 points
Devoted Protector: Do 25k healing while defending a capture point 200 points
Sublime Protector: Do 57.5k healing while defending a capture point
Divine protector: DO 375k healing while defending a capture point

Chaosball
Ball buster: Score a 11.75k hit on a chaosball carrier
Chaos hunter: Kill a chaosball carrier (repeatable) 100 points
Chaos mender: Score a 5k healing hit on a chaosball carrier (repeatable) 100 points
Chaos bruiser: Deal 5k damage to chaosball carriers 50 points
Choas devastator: Deal 25k damage to chaosball carriers 100 points
Chaos destroyer: Deal 50k damage to chaosball carriers 200 points
Chaos champion: Deal 500k damage to chaosball carriers
Assist: Help kill a carrier 100 points
Chaos protector: Do 5k healing to chaosball carriers 100 points


I'm not sure on the points received for some of the medals. Feel free to chime in with how many they give.