Yes, this is a continuous effect. The concentration check DC is dependent on the damage you suffer that round.

So what's the concentration check on 4 damage?

The DC is 10+half of the damage last dealt+level of spell attempted to cast.

See: http://www.d20srd.org/srd/skills/concentration.htm

Concentration: 29 (pass)

Round 11:
  [Move] Move 70' to C03
  [Free] Power Word Pain Damage: 1

Status:
  Initiative: 10
  AC (Touch AC): 20 (14)

  Damage Taken:
  Damage Dealt: 13

Effects:
  *Twin Sword Style: when wielding 2 weapons choose target and get +2 to AC vs that target.

 Mirror Image: 5 extra images

 Expeditious Retreat: +30' to movement (4 minutes)

 Power Word PAIN: 11 rounds

Final Position: C03
This message was last edited by the player at 16:04, Wed 06 Mar 2013.

Levis saw the elf move up through the halls, opposite the place she last spotted him. He moved impossibly fast, and that was concerning. She had to be smart to catch him. Smart and reckless. Throwing caution to the wind, she decided to try something she was told to never do unless it was the only means of survival. Moving quickly, she moved right against a wall, and then attempted to flicker past it. She arrived on the other side of not the first wall, but a second, and shockingly, a lot closer to the elf than she was comfortable with. In her panic, she let loose her shadowy gaze.

Round 11:
 [Move] to G7
 [Swift] Flicker to F4
 [Standard] Killing Shadows 25 damage, Will DC17 to half. (concentration 26)

Status:
 Initiative: 3
 AC: 17(11)

Damage Taken: 13
Damage Given:

Effects: Steel Shadows (+6 AC,), Caul of Shadows (+2 AC), Piercing Sight (See invis, Darkvision 60'), Flicker (5 rounds).

Final position: F4

In reply to Levis Luna (msg # 60):

OOC: Don't you have to roll to hit me or one of my images? There are 6 Adamars.

It's a 30ft cone. I choose all of them.
This message was last edited by the player at 22:49, Wed 06 Mar 2013.

OOC: Ok then, make a WILL save vs DC 14, please.

Will Save: 19

As Adamar recognized the spell that did so much damage to Zar'Da the elf cast a quick spell trying to cause Levis to stop her casting, which he realized failed as soon as the shadow washed over him...

Round 11:
  [Immediate] Cast Stay the Hand (Levis Saved)

The elf let out a muffled gasp as the shadow tugged at his very soul.
"w-w-w-w-well that w-w-w-was f-f-familiar." Adamar stammered as he raised his hand and fired off two energy missiles at the young woman just before he took off running across the arena once again.

Round 12:
  [Standard: Activate Gloves of the Starry Sky: Give up spell slot for Magic Missile: 2 missiles for 8 damage
  [Move] Move 70' to O16
  [Free] Power Word PAIN damage: 2

Status:
  Initiative: 10
  AC (Touch AC): 20 (14)

  Damage Taken: 25
  Damage Dealt: 23

Effects:
  *Twin Sword Style: when wielding 2 weapons choose target and get +2 to AC vs that target.

 Mirror Image: 5 extra images

 Expeditious Retreat: +30' to movement (4 minutes)

 Power Word PAIN: 10 rounds

Final Position: O16

Levis saw him take off with impossible speed once again, and if she was him, she'd move as far away as possible. Hopefully she had enough time to catch him once more, since her injuries were catching up with her. The pain from the spell had started a small nosebleed and there were four burn marks on her from magic missiles. All in all, she was in rough shape. She flickered back to where she came from, and moved with haste to somewhere she could reach him from if he moved far away.

Round 12:
 [Swift] Flicker to G7
 [Move] to K7

Status:
 Initiative: 3
 AC: 17(11)

Damage Taken: 23
Damage Given: 25

Effects: Steel Shadows (+6 AC,), Caul of Shadows (+2 AC), Piercing Sight (See invis, Darkvision 60'), Flicker (4 rounds).

Final position: K7
This message was last edited by the player at 09:49, Thu 07 Mar 2013.

Adamar decided to take the chance to finish this match. Moving into view the Beguiler fired off one more set of missiles.

Round 13:
  [Move] Move 30' to I14
  [Standard]: Activate Gloves of the Starry Sky: Give up spell slot for Magic Missile: 2 missiles for 6 damage
  [Free] Power Word PAIN damage: 3

Status:
  Initiative: 10
  AC (Touch AC): 20 (14)

  Damage Taken: 25
  Damage Dealt: 32

Effects:
  *Twin Sword Style: when wielding 2 weapons choose target and get +2 to AC vs that target.

 Mirror Image: 5 extra images

 Expeditious Retreat: +30' to movement (4 minutes)

 Power Word PAIN: 9 rounds

Final Position: I14

Levis was barely holding onto consciousness, but she saw her chance and leaped at it with all her strength. She flickered closer to close some of the distance and put the elf into range. Drawing upon all of her power, and ignoring the pain, she focused all of the power she could muster into one final blast.

Round 13:
 [Swift] Flicker to J10
 [Full round] Maximized Killing Shadows. 48 damage in a 30ft cone. Will DC17 to half.
 [Concentration check vs DC19(?)] 24

Status:
 Initiative: 3
 AC: 17(11)

Damage Taken: 32
Damage Given: 25+48

Effects: Steel Shadows (+6 AC,), Caul of Shadows (+2 AC), Piercing Sight (See invis, Darkvision 60'), Flicker (3 rounds).

Final position: J10

OOC: No joke. I barely lived.
This message was last edited by the player at 15:14, Thu 07 Mar 2013.

Dead, congrats once again.

I have a question. Why haven't you tried to hit me physically?

I'm tempted to call this a draw, since Levis will still suffer the effect of the spell even after the fall of Adamar.

That's a fair ruling. I was wondering if the effect of Pain would endure after he died.

Because with Flicker and your Killing Shadows I would never be able to get far enough away. I didn't realize you had more than one use of Flicker, that's why I tried to stay away from you as much as possible. And you NEVER seem to miss a WILL save so none of my other spells would work on you. Doesn't really seem to matter with your massive damage spells. I may just have to have a match with you against Orophear just to try and get at least one win with one of my characters :/

SOLO: I believe she only has one hit point left. I was hoping to roll a 7 on MM but luck has never been my strong suit.

It does, since he just utters the word and doesn't have to concentrate or really do anything else. Compare with spiritual weapon, which attacks on its own every round, but the target has to be in sight of the caster. In a similar situation, the weapon would return to the caster and hover above the fallen form.

So, a draw then?

Yes, if you are all ok with it. A technical draw if you will.

I'm good with that, although I was the one that fell first :)

Yep. I'm totally okay with that. I don't feel like I should have beat you.

If you had waited for me in your corner, I wouldn't have been able to metamagic that, and you might have lived, and won.

Grrr, I was teetering between healing/waiting and pushing the attack to try and put you out. I knew I should have just waited. Oh well, lesson learned. We should fight together at some point :)