First of all let me say this is a well earned achievement.
Now then my advice is for someone:
- who doesnt have shale
- who is warrior class with heavy armor
- who is the last member alive of his group
- who specializes in melee, but 2 handed vs 1 handed
- who has less than five healings
Basically as you can tell from my above comments, i did not have the dlc so i did not have shale, I was a warrior class and preferred melee, and well my party was absolutely worthless.
The key here though is if you go the route of two handed melee, you have to build up your dexterity so you can eventually use the skill two normal one handed weapons in both hands, vs one normal and one dagger. Now let me tell you this skill is absolutely worthless in this battle. You can basically complete forget about up close melee even heavily armored because the dragon is too fast, he can whip around so fast you dont have time to hit him, his tail knocks you back, and if you face him head on there is the chance of the dragon grabbing you in the mouth, this is basically an instant kill.
Additionally, most of your party is ultimately useless because the dragon moves around by flying to often and easily gets to your other party members. There is no truly safe area to place your characters, near the gong or otherwise.
So basically you are screwed, right? No luckily enough building dextrity allows even you melee warrior to use fairly decent bows. Thats the first step of the tactic. Note make sure to have several hundred arrows because while you can use the bow, your damage is weak so dont run the risk of running out of arrows. If you were like me and never bothered with bows, you can get arrows and some bows at the stores. Id say around 150-200 arrows is more than enough.
Now the actual battle, just let your party do whatever while they are alive, you can just run around and do whatever until most of your characters are dead, if lucky they should be able to take away close to half of the high dragons life.
Now step 2 : If you have the store of arrows, you can now actually beat the dragon without ever taking another hit. First run behind the rock to the right of the gong (facing towards andrases tomb), you can get off a hit, but almost immediately the dragon takes off and will and where you are. Simply run down the to your right, and hide behind the little bump of a rock just behind the small crevacie/cliff face of where you were. The dragon will then adjust and fly to where you are, but run back to the original spot. Basically you have enough to time to pluck off one arrow which will do around 23 damage, or 56 if you score a critical. So basically its a battle of will and just continue running from the spot to spot plucking one arrow at each time. As long as you shot off only one arrow you have more than enough time to avoid the dragon and get back to the other spot. Ill admit it takes a long ass time, but at this point in the game you do not have the advantage to learn ranged attacks to make the battle easier. And although the battle is long, if you dont run out of arrows the dragon will go down within 15 minutes or so, for an rpg player a battle of this length is not to long.
There is only one caution, if you are out of place by a little bit, the dragon can use its wings to knock you down and pull you closer. Luckily, if you are on top, the edge of the cliff/crevasse prevents you from going any further, but you might get hit with a little fire. If you are on the bottom part even easier, the dragon pulls you against the cliff face and shots fire over the top of you. In any case if this happens i suggest not trying to adjust and get a shot off, and rather just running to the next place, you wont get killed if you get hit with some fire even with low fire resistance but there is no need to risk anything.
Eventually after rope a doping the dragon like this for around 7-15 mins it goes down, and at level 18, you gain about 222 xp , the dragon scale and i think one other unique, and mainly the achievement.
Note: when the dragon looks like it has a couple of hits left, you can risk switching to your normal weapons and try to get off a few melee hits, however this runs high risk, especially if you die and lose a lot of time. I thought about this, but scrapped the idea and just continued shooting arrows.
Like I said its not pretty but its basically full proof, and allows you to get around playing as a warrior.
Now one other note, i honestly dont use bows at all, so i cant tell you whether there is a bow with low enough dexterity, the strategy of not getting hits works for any massively heavy armor wearing warrior, so even if you dont have high dexterity you might luck out and find a bow with a low enough requirement to use. Additionally some vendors sell tomes which allow you one free skill point, there are enough i believe for 5 or 6, so like i said maybe you can find a weaker bow. Remember though if use this weaker bow it might take even longer so take more arrows, but eventually the dragon goes down.
And one last note, personally I dont think the dragon plate armor you get from the scale is that much better than Juggernaut armor, so if you dont want the achievement Id skip the battle, I dont think the reward is that great.