Killing an Half-Fiend Ancient Red Dragon using a Paladin

[Spore]

Greetings playground,

our archnemesis is an LE half-fiend Ancient Red Dragon (with personalized spell list, so far she has used Greater Teleport) and we have houseruled Dragons to be shapechangers that have a fixed humanoid form. The setting is pretty "dark magic and steampunk" which is cool and all but it annoys (and motivates) me to some extend that the DM throws all powerful villains at us. So far we have a red dragon BBEGal, an adult black dragon as quest giver, an high level orcish warlord with an axe able to create a gigantic antimagic zone and a necromancer who cannot die (he's not a lich, he has a watch that constantly revives him if slain).

And most of all do I want to end the neverending argument on our table: "You cannot kill well played dragon."

I want to give my DM a run for his money and I will have to use my T4/5-ish Paladin 7/Cavalier 4 (using a Gryphon mount) for it. I want to use the power of Smite Evil to kill her the next time I get a chance to do so. Do you have ANY pointers for that? We need to remove possible buffs (our cleric could prepare greater dispel magic) need to reliably hit her AC (40ish) and survive the setup turns as well as hand to hand combat.

I wanted to try to use Spirited Charge combined with Challenge, Smite Evil, Power Attack, Furious Focus and Radiant Charge (but apparently only the Charisma to damage gets multiplied, so is Risky Striker better for a Halfling?) using my +1 Holy Lance to burrn through her 500ish HP. The problem is that the first (and most powerful hit) only does deal about 180 damage, with Smite Evil being halfed after that attack.

Is there a way, a spell (for a cleric of 11th+ level) or an item to severely wound or tilt the fight in our favor BEFORE the DM intended her downfall?

Some stats:

Halfling, ergo small size
Str 14 Dex 14 Con 16 Int 12 Wis 10 Cha 16 (Items are Str +2/Cha +4), Paladin 7/Beast Rider 4
Gear: Giant Killer (Small Longsword/Medium Shortsword +2, gets additional bonus for every size your enemy is bigger than you), +1 Holy Lance, Mithril Breastplate +1, Mithril Shield +1, Ring of Protection +2
Feats: 1. Mounted Combat 3. Power Attack 5. Ride-By Attack 7. Furious Focus 9. Spirited Charge 11. ???
Order of the Stars (counts as 9th level Paladin for Lay on Hands

[danzibr]

Is it just you and your Cleric buddy?

I'd suggest having your other caster buddy doing some Shivering Touch, then you cdg.

[ninjamaster1991]

Yeah, a (Maximized/Empowered/etc.) Shivering Touch, followed by repeated Coup de Graces seems like your best bet here.
Unless you can somehow afford to arm hectopeasants with Dragonsbane/Devilsbane bows...

[endur]

Scroll of Holy Sword (level 4 paladin spell)

[FocusWolf413]

If you want to debuff it, hit it with a reciprocal gyre, from Complete Arcane. It does (Spell levels affecting dragon)d6 damage, will save half. Dispel/Greater Dispel also works. I forget what spell it is, but some spells prevent a dragon from using it's breath or flying. There's a spell that hides you from dragons, but the name of that spell also eludes me.

Use true strike and wraith strike. They'll let you use your full Bab for power attack.

EDIT: I think those are all wizard spells.

[BWR]

Some people seem to be missing the Pathfinder tag.

Yes, Risky Striker is much better. You will be hit easier to hit but LoH is generally far more useful for healing than damage, especially at the trade-off from Radiant Charge. If you could reliably crit it would be worth it, and it might possibly be worth it if you are just a few hp away from killing the dragon.

Spell-wise, GDM is a must, preferably several. Remove active spells that boost AC and suppress magic items like Rings of Protection or Belts of Dexterity. You might also look into getting a Planar Ally. Getting a Movanic Deva (http://www.d20pfsrd.com/bestiary/monster-listings/outsiders/angel/angel-movanic-deva) who flies in with an active AMF and stays so it's covering the dragon but not you so you can charge it can effectively shut down a lot of the dragon's powers so long as the dragon doesn't fly away. The chalkydri (http://www.d20pfsrd.com/bestiary/monster-listings/outsiders/angel/angel-chalkydri-tohc) is another nice choice, if your DM allows Tome of Horrors.

Apart from that, obvious things like Resist/Protection from Energy, Freedom of Movement, Dimensional Anchor.
Oh, and hope that you can trick it to go indoors or underground so it can't use its speed advantage.

[Spore]

Some people seem to be missing the Pathfinder tag.

Yup, they do.

I fully expect her to have several millions worth of magical items. Also does the DM have a knack for picking the right spells and exchanging feats to make his creature more potent.

1) AMZ: I feel Antimagic Zone is a spell she has.
2) She instagibs me with Blasphemy (Half-Fiend Template, me being good).


Apart from that, obvious things like Resist/Protection from Energy, Freedom of Movement, Dimensional Anchor.
Oh, and hope that you can trick it to go indoors or underground so it can't use its speed advantage.

We have one advantage. We know where the quest McGuffin is to destroy/save the world. So we can reliably lure her anywhere granted we have the girl and risk everything (since no one in our groupe can bluff decently).