Rune Leveling, What we know so far...

[Omnipotent2013]

Note- * means usage in battle increased by 1

Brutality lvl 1 3% + 200 damage
1k Exp
lvl 2 4%+ 400 damage
lvl 3 5% +600 damage
lvl 4 6%+800 damage
lvl 5 7%+1000 damage
3750 exp
*lvl 6 8%+1200 damage
lvl 7 9%+1400 damage
lvl 8 10%+1600 damage
lvl 9 12%+1800 damage
*lvl 10 15%+2000 damage

Bleed lvl 1 Random enemy loses 3% Hp lasts 3 turns max 1500 damage
3k exp
lvl 2 3% hp, 4 turns, 1500 damage
lvl 3 4% hp, 4 turns, 2500 damage
7500 exp
lvl 4 4% hp, 5 turns, 2500 damage
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10 8% Hp, 8 turns, 8000 damage

Chaos lvl 1 90% damage, 30% chance to turn enemy, lasts 1 turn
10k exp
lvl 2 100% damage, 30% chance to turn enemy, lasts 1 turn
lvl 3
lvl 4
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10 100% damage, 100% chance to turn enemy, lasts 3 turns

Rage lvl 1 30 rage
10k exp
lvl 2 35 rage
lvl 3 40 rage
lvl 4 45 rage
lvl 5 50 rage
*lvl 6 55 rage
lvl 7 60 rage
lvl 8 65 rage
lvl 9 70 rage
*lvl 10 80 rage

Amnesia lvl 1 90% damage, 50% chance to prevent target to use a skill, lasts 1 turn
10k Exp
lvl 2 100% damage, 55% chance to block 1 skill for 1 turn
lvl 3
lvl 4
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10 100% damage, 100% chance to prevent enemy using 5 skills lasts 3 turns

Heal lvl 1 10% heal
lvl 2 12% heal
lvl 3 14%
lvl 4 16%
lvl 5 18%
*lvl 6 20%
lvl 7 22%
lvl 8 24%
lvl 9 26%
*lvl 10 30%

Guardian lvl 1 Decreases damage taken by 10% lasts 2 rounds
lvl 2
lvl 3
lvl 4
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10

Purge lvl 1 Dispels 1 positive buff off 1 enemy
lvl 2
lvl 3
lvl 4
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10

Purification lvl 1 Dispels 1 negative buff
lvl 2
lvl 3
lvl 4
lvl 5
*lvl 6
lvl 7
lvl 8
lvl 9
*lvl 10

All Runes at max level can be used 3 times

If you have the guardian rune, Purge rune, or Puri rune please post and I'll add it to the list of what more levels do

[Omnipotent2013]

Also, mages can't use the purification rune, Archers can't use the purge rune, and knights can't use the guardian rune.

[djordaek]

Brutality lvl 7: 9% +1400 2 turns

[Telstar]

Wikia is quite updated on this

[SinnedWill]

Bleed Rune Lv. 5 = 2 uses, 5 turn duration, 5% max HP of target as damage, 3500 max per round, requires 22,500 exp to lv. 6
Bleed Rune Lv. 6 = 2 uses, 6 turn duration, 5% max HP of target as damage, 3500 max, requires ? to lv. 7

Purge Rune Lv. 1 = 1 use, dispels 1 positive buff from 1 random enemy, requires 6k exp to lv. 2
Purge Rune Lv. 2 = 1 use, dispels 1-2 positive buffs from 1 random enemy, requires ? exp to lv. 3
Purge Rune Lv. 10 = 3 uses, dispels 3 positive buffs from ALL enemies

[Setsuna88]

Heal rune can be used twice at lvl 4 already

[Telstar]

Purification 6k for lv2.