You're looking at playing a Warder then, preferably Zweihander Sentinel. you also want to gain access to Mithral Current somehow; I use bushi, but just traiting into it would be fine too. that one should replace Golden Lion, so that you have access to Mithral Current, Primal Fury, Scarlet Throne, and Iron Tortoise.
The reason for Iron tortoise is for two things - the first is Burnished shell, which lets you parry spells, which is pretty awesome, though the other counters in IT help. The second is Turtle General's Stance, which lets you become immune to breath weapons.
Scarlet Throne is useful for two other things - Sanguine Perseverence, which is one of the best counters in the game as it replaces your saving throws with a Sense Motive check. The other is Scarlet eye's Perception, which lets you make your next attack a touch attack.
Mithral Current is there for more counters, but for a good reason; the DODGEROLL counters allow you to negate enemy full-attacks by moving out of its threatened range, which is hugely important for evading the as many as eight attacks a dragon in full-attack mode might level at you.
Finally, Primal Fury is where your damage is at; Impaling Strike and Blood-Spray Strike are the biggest ones because they allow you to deal constitution damage. this is fucking important, because massive creatures (such as fully grown dragons and linnorms) have hugely inflated HP pools due to massive constitution and very high HD, but if you're dealing constitution damage, you're using its own high HD numbers against it; 2 con damage is equal to 1 damage for every HD it has and, for example, which is 24 extra damage versus a tor linnorm. and Scarlet Eye's Perception lets these strikes hit as touch attacks, which is amazing.
You no sell everything, roll out of the way when it wises up and then stab it in the fucking heart. Just make sure to bring a ring of Freedom of Movement, or it'll just grapple you, but otherwise... yeah.