
Kirche |

1d20 + 11 ⇒ (5) + 11 = 16 - Spellcraft
Not wanting to lose sight of her target, Kirche quickly attempts to counter the spell as it's being cast.
1d20 + 10 ⇒ (11) + 10 = 21 - Using dispel magic for DC 21
Having foiled her opponent's attempt at becoming invisible, she casts an offensive spell.
Kirche casts Icy Prison.
You find yourself encased in 10-inch thick ice. Reflex DC 23 to avoid being helpless. If you make the save, you're entangled. Either way, take 10 pts of cold damage.
Ice has 30 hp and DC 25 str check to break

Kirche |

Such a fate, to slowly freeze to death encased in ice. I honestly didn't expect you to fail your reflex save, and was mostly using the spell for guaranteed entangle, making your successive spell casting more difficult. I just got lucky. Also, you can have a significant boost to the counterspell if you also have the exact same spell. Not guaranteed, but at least a lot more likely - so it makes it worthwhile to go for the less obvious or more obscure spells.
So that's 1-1 using the spell duel rules. Tie breaker?
1d20 + 11 ⇒ (16) + 11 = 27 - Inititative

Mr. Swagger |

Spellcraft DC 20
con damage1d4 ⇒ 3
pulls rod out as a move action
edit:correct link to map
map is updated. The green area is the bad area.

Kirche |

1d20 + 11 ⇒ (16) + 11 = 27 - spellcraft
Kirche attempts to counter the incoming spell.
1d20 + 10 ⇒ (19) + 10 = 29 - Using dispel magic for DC 21
She manages to stop the spell just as she smells the first hints of poison gas, and retaliates with a spell of her own.
Casts Feeblemind
Will save DC 32 to resist.

Mr. Swagger |

spellcraft:1d20 + 11 ⇒ (3) + 11 = 14
dispel:1d20 + 10 ⇒ (15) + 10 = 25
He can't identify the spell so he goes to dispel magic as the defacto option.
Spellcraft DC 18:
fire damage:10d6 ⇒ (1, 1, 1, 5, 2, 4, 1, 3, 2, 1) = 21
Reflex save DC 23 for half
Make 2 saves or be dazed for 3 rounds.
edit:The dice gods surely hate me with crappy damage rolls like that.

Kirche |

Hey, at least you made the dispel check - that's what's important
1d20 + 11 ⇒ (3) + 11 = 14 - spellcraft
Also has no idea what's being cast, so she uses Dispel Magic
1d20 + 10 ⇒ (8) + 10 = 18 - dispel vs DC 21
and fails to counter the spell.
1d20 + 13 ⇒ (20) + 13 = 33 - reflex
1d20 + 13 ⇒ (5) + 13 = 18 - reflex
Ouch! Kirche is dazed!

Mr. Swagger |

Feeling confident with his enemy in all sorts of trouble:
move action: move to P16
Standard action:
Grapple check:1d20 + 15 ⇒ (6) + 15 = 21 CMD to break free=25
damage:1d6 + 4 ⇒ (3) + 4 = 7
concentration check to escape if you are alive-->25+spell level
--------------------------------------------------
2nd Round
Grapple check:1d20 + 15 ⇒ (14) + 15 = 29
damage:1d6 + 4 ⇒ (5) + 4 = 9
Move action: move to L12
Standard action:
Fire damage: 10d6 ⇒ (3, 3, 3, 6, 3, 4, 4, 1, 3, 2) = 32
Reflex save DC 23 for half
Make 2 saves or be dazed for 3 rounds.
-----------------------------
last free round unless save was failed.
Grapple check:1d20 + 15 ⇒ (18) + 15 = 33
damage:1d6 + 4 ⇒ (4) + 4 = 8
Move action: move to H8
Standard action:
ranged touch attack:1d20 + 9 ⇒ (2) + 9 = 11
negative levels:1d4 ⇒ 4
You now only have access to your 3rd level spells and your caster level is effectively only a 6 unless you have a way to remove the negative levels.

Kirche |

Dazed 2/3, 42/70 hp, grappled
-------------------------
1d20 + 13 ⇒ (4) + 13 = 17 - Reflex
1d20 + 13 ⇒ (12) + 13 = 25 - Reflex
Dazed 1/3, 1/70 hp, grappled
-------------------------
Dazed 2/3, -7/70 hp, grappled
Kirche falls prone, and though the touch attack misses, she is dying. Even if she stabilizes she has no way to get back to positive HP before you (or the tentacles) finish her off. Well done.

Mr. Swagger |

Check the dueling rules in ultimate combat. Myself and the other poster agreed on no summons because they are an insta-win.