Tutorial Vanguard is quite easy if you are proficient at dodging, as you need to get out of the way from his first two swings and position yourself in an Southwestern position near his left leg.

This will cause a glitch in the Vanguard AI, and the only move he'll ever use is the Flying butt stomp which is fairly easy to dodge. Just kept hitting him, whenever you see him fly, get away, and when he hits the ground immediatly go back to hit him. I've killed him with pretty much every class using this, even the painstakingly slow Temple Knight. 

I don't wanna get into specifics here cus I don't think khuutra would appreciate us spoiling the boss for him

but lolol it DOES have a POWERFUL ATTACK...what are you talking about (unless thats the gravity attack your talking about which it may be)...spoilers below:

He did have ONE big attack (which IS a powerful attack) that killed my lightning in one hit if that stupid tail put the status ailments on her

You know the one where it does an animation & does around 5K - 6K damage.....seriously that IS a powerful attack lol

Then the cheap death thing.......that cheap move alone warrants a 0.1 point taken away from the games total score!!

The enemies in the final dungeon were pretty easy actually....you had to make effective use of sentinels & be prepared to spend ages in a battle..thats all

Actually I didn't even use a guide for this one :P 

First time I went through the game as a Knight I managed to get him to half his HP before his swing hit me.

Flamelurker is an entirely different beast. He gets harder and harder as each new NG+ comes and goes. On NG+5 his AoE fire spell can take over 800 HP, even with 450 Fire Resistance like my Platinum Character had. I managed to beat him all the time in a straight fight though, with the Dragon Bone Smasher +5 and Sticky White Stuff.