I actually threw a quick build together with your guidelines in mind, langeweile, and I think you may have sold it a bit short: I'm coming up with a bit more damage.
Dwarf Battlemind
Dwarf Battlemind/Son of Mercy/Demigod:
L1 – Str 14, Con 18, Dex 13, Int 8, Wis 16, Cha 10
L4 – Str 14, Con 19, Dex 13, Int 8, Wis 17, Cha 10
L8 – Str 14, Con 20, Dex 13, Int 8, Wis 18, Cha 10
L11 – Str 15, Con 21, Dex 14, Int 9, Wis 19, Cha 11
L14 – Str 15, Con 22, Dex 14, Int 9, Wis 20, Cha 11
L18 – Str 15, Con 23, Dex 14, Int 9, Wis 21, Cha 11
L21 – Str 16, Con 26, Dex 15, Int 10, Wis 24, Cha 12
L24 – Str 16, Con 27, Dex 15, Int 10, Wis 25, Cha 12
L28 – Str 16, Con 28, Dex 15, Int 10, Wis 26, Cha 12
Feats:
L1 – Melee Training (Constitution)
L2 – Dwarven Weapon Training
L4 – Weapon Expertise (Hammers)
L6 – Defender of the Wild (Perception)
L8 – Crippling Crush
L10 – Wintertouched
L11 – Lasting Frost
L12 – Hammer Rhythm
L14 – Armor Proficiency (Plate)
L16 – Dwarven Durability
L18 – Improved Initiative
L20 – Paragon Defenses
L21 – Devouring Demand
L21 – Robust Defenses (replaces Paragon Defenses)
L22 – Armor Specialization (Plate)
L22 – Superior Initiative (replaces Improved Initiative)
L24 – Rapid Mind Spike
L26 – Prescient Retaliation
L28 – Epic Reflexes
L30 – Epic Fortitude
AC: 48 --> 10 base, +15 levels, +14 armor, +6 enhancement, +2 shield, +1 feat
Fort: 48 --> 10 base, +15 levels, +9 ability (Constitution), +6 enhancement, +4 Epic Fortitude, +2 feat, +2 item
Ref: 41 --> 10 base, +15 levels, +2 ability (Dexterity), +6 enhancement, +2 feat, +2 shield, +4 Epic Reflexes
Will: 45 --> 10 base, +15 levels, +8 ability (Wisdom), +6 enhancement, +2 class, +2 feat, +2 item
HP: 217 --> 15 base, +174 levels, +28 ability (Constitution)
Bloodied: 108 HP or less
Healing Surges: 20 --> 9 base, +9 ability (Constitution), +2 Dwarven Durability
Healing Surge Value: 63 HP
Initiative: +30 --> +2 ability (Dexterity), +15 levels, +8 feat, +5 item
Magic Items (Expected GP = 14,625,000):
L29 (2,625,000 gp): Ring of Free Time (AV 2)
L28 (2,125,000 gp): +6 Frost Craghammer (PHB)
L28 (2,125,000 gp): +6 Frost Throwing Hammer (PHB)
L28 (2,125,000 gp): +6 Steadfast Amulet (AV)
L27 (1,625,000 gp): +6 Dwarven Godplate Armor (PHB)
L26 (1,125,000 gp): Iron Armbands of Power (Epic Tier) (AV)
L23 (425,000 gp): Eye of Awareness (AV)
L22 (325,000 gp): Siberys Shard of Merciless Cold (Epic Tier) (EPG)
L22 (325,000 gp): Siberys Shard of Merciless Cold (Epic Tier) (EPG)
L21 (225,000 gp): Gloves of Ice (Epic Tier) (AV 2)
L20 (125,000 gp): Diamond Cincture (Paragon Tier) (AV 2)
L18 (85,000 gp): Planestrider Boots (MOTP)
L13 (17,000 gp): Ring of Giants (D 378)
L9 (4,200 gp): Backlash Tattoo (AV 2)
Nonmagical: Heavy Shield (PHB)
TOTAL: 13,271,200 gp
Attack Bonus Sources:
+15 (Level)
+9 (Constitution)
+6 enhancement (+6 Weapon)
+3 feat (Weapon Expertise)
+2 (Combat Advantage)
+2 (Proficiency)
Total: +37
Damage Bonus Sources:
+9 (Constitution)
+9 (Crippling Crush)
+8 (Lawbreaker’s Doom)
+6 enhancement (+6 Weapon)
+6 item (Iron Armbands of Power)
+5 (Lasting Frost)
+5 (Siberys Shard of Merciless Cold)
+4 (Gloves of Ice)
+2 feat (Dwarven Weapon Training)
Brutal Barrage: +37 vs. AC with CA
Hit: 31 cold damage
Critical: 6d6+43 cold damage
Miss: 9 damage
Brilliant Recovery: +37 vs. AC with CA
Hit: 2d10 (brutal 2) + 54 cold damage
Critical: 6d6+86 cold damage
Miss: 9 damage
DPR: (3)*(0.65)*(31) + (3)*(0.05)*(64) + (3)*(0.30)*(9) + (1-[1-0.30]3)*(2)*([0.65]*[67] + [0.05]*[107] + [0.30]*[9]) = 145.95 DPR
DPR (1 PP expended): (4)*(0.65)*(31) + (4)*(0.05)*(64) + (4)*(0.30)*(9) + (1-[1-0.30]4)*(2)*([0.65]*[67] + [0.05]*[107] + [0.30]*[9]) = 182.62 DPR
DPR (1 PP expended, after milestone): (4)*(0.65)*(31) + (4)*(0.05)*(64) + (4)*(0.30)*(9) + (1-[1-0.30]4)*(3)*([0.65]*[67] + [0.05]*[107] + [0.30]*[9]) = 221.83 DPR
Suffice to say, very impressive, and likely worthy of its own thread, wouldn't you agree?
As for Radiant, I don't think it'll generate much more single target oomph this will; going for Morninglord and Radiant Advantage results in less damage than this (though it is markedly less feat-intensive, there's not all that many damage options for something that doesn't have a damage roll), and Headsman's Chop is kind of situational here (two or more BB attacks have to hit for that to happen, and giving up on Hammer Rhythm means you're likely treading water or worse on the DPR front).