I unleashed all dragon roar attacks on him one by one and he blocked every one of them using normal attacks and also took some damage. Either he was trying to confuse me by showing that he can use limited dragon roars or he really can use limited number.
As my dragon related moves don't require mana but it take a little toll on my physical body. So I went for all in to attack him with special sword close combat moves. I covered my dragon sword with light mana as it is opposite to dark mana and unleashed '100 Slashes' skill followed by '100 stabs' skill and he blocked almost everyone of them. I finished it with a strong blow and he blocked it which pushed him back a little.
The king covered his sword with dark mana and started attacking me. His attacks were quite powerful. Even I was blocking them but they are still damaging me. I was enduring them so that I can use 'momentum rush' on him.
As I was blocking his attacks, I was also trying to cover my sword with fire mana. I successfully managed to cover my sword with fire mana and used 'Dragon Sword Special Fire Berserk', using this move my fire attacks will deliver double damage for 15 minutes. This time both of us are attacking eachother. As everyone say 'Attacking is the best method of defending.' I don't remember clearly but it was something similar like this.
After 10 minutes of continuous brawl, I finally broke his defence and unleashed my attacks on him for 5 minutes straight. Whenever he tried to recover or tried to defend, I attacked him with more power. So he can't recover from my attacks.
Finally 30 minutes are completed and there is still 4-5 minutes remaining in my fire berserk attack and I used my 'Momentum Rush' skill. As my attacking power is doubled, king realised my strategy and to escape from it he launched 'dark dragon's roar' in short range. I sliced that roar attack in middle. In the mean time he escaped from there.
My momentum was broken and my fire berserk time limit was also finished. I have to finish the king before he recover anymore. I have to use 'Sword Rush' which will increase my attack damage into six times as I was already using 'Momentum Rush'.
The king had taken a huge damage and he realised his end. He laughed,
'Ha ha ah' (x5)
I don't want to give him any more time to recover. I covered my sword with wind mana and unleashed 'Dragon Sword Special Wind Blaze' which deliver powerful concentrated wind attack.
The impact will be so powerful that its impact will also give damages to the foes. I used couple of this attack on him. The king then again used his 'Dark dragon's roar' and I again slashed it from middle and quickly rushed towards him and used my 'sword dance', '100 slashes" and other normal attacks on him.
As the time limit of Sword Rush' was reaching near, I flew and launched 'Light dragon's roar' on the king. This time king was not able to block it properly. The king was completely covered in blood and his wounds expanded after my dragon roar.
The king uttered his final words, "I was not able to protect my world. But you have to protect your world. Take my 'Dark Dragon Sword' and use it to end your world's apocalypse. Don't end into misery like us. You have to save your world." He then slowly disintegrated into air.
Notification popped saying,
"You have successfully defeated the boss of this dungeon."
"As a reward, you got dark dragon sword because of the king Archanamesh's wish."
"You also received some skills of Archanamesh."
"Ultimate block, using this you can block any attack but it will consume 2k mana and can be used thrice within 12 hours only."
"Dark orbs, using this attacks you can produce dark orbs with concentrated mana and it consumes 1500 mana for each orb."