What a strange fight, tons of health, lots of spells with a good chunk of damage considering how early-game it is. i managed to beat him by kiting him around pillars, so he couldn't see me...almost like he forgot i existed as soon as i was behind the pillar.

for the forest of the fallen giants encounter i just used the ladders around me and kept hitting him with spells

His weakness is melee, when he is not casting he sometimes will pull out his sword and hold his shield up, guard break him and you can riposte him for high damage. be careful because he is programmed to snap back up and attack you really quickly after a Back stab or riposte.... much faster than you can heal. Armourer Dennis has over 90 Int, ~3800HP in Iron Keep and can use Soul Vortex, Soul Geyser(rare OKO) , Soul spear, Soul bind and Soul Greatsword and they all hit hard. these are all player spells that can be used against you in PvP so get used to dodging them. he can be cheesed with a rebels great sheild but you want to force him to melee, at close range he can use Vortex and Bind. if not he will try to go you with is sword. wait until he raise his shield guard break and riposte . he is also susceptible to backstabs when casting spells