Huh? The tentacle monster for me only showed up
.
And LOL you took the LONG way to the fortress, and met the dragon like me! I found out you're actually meant to go westward from Gran Soren, there's a Quarry there, a shortcut that bypasses alot of the horrors in South Gransys including the dragon.
Also, I noticed your style of fighting is very different from mine, here's what I use for Strider's melee (note that two of them can be used by any class that uses daggers):
Primary Skills (Daggers)
LMB - Biting/Cutting/Shearing Wind - ESSENTIAL combat skill, dash forward and strike repeatedly at an enemy at all sides, very useful against shield guys too as you get them in the back and stagger-lock them. Good for evasion as well as closing the distance quickly too.
RMB - (Class dependant, evasion/block/CC skill)
E - Scarlet/Hundred Kisses - VERY useful for large enemies as it's the only dagger skill you can use when climbing, and if you keep tapping it, it's constant DPS without the stamina drain as long as you keep slicing. It does ALOT more damage than simple light or heavy attacks.
Tip: When climbing enemies I get to a weak spot first, and then go crazy with scarlet kisses slicing non-stop. More DPS that way.
Another tip: Get the core skills that improve your light/heavy attacks, they stagger much better.
BTW, Magick Archer vocation is sooooooooooooo.... OP with homing arrows and ability to lock onto multiple enemies at once! And that dagger-shockwave skill is so awesome.
Now that I'm confident with the mechanics I actually restarted the game on hard mode, but the hard mode was like NG+ so it used all my equipment and xp... I didn't want that - so I started a new game, and then switched to hard mode which meant I'm playing hard mode starting lvl ONE 
Stepped outside the village and got one-hitted by a goblin! lol
But now lvl 15, rank 6 strider and just reached Gran Soren, gameplay is more unforgiving of mistakes sure but I like it 
Surprised there's mods for Dragons' Dogma, just checked the nexus... and what do you know, there's a nude mod... of course! lol
I might upload a battle myself later.