On which difficulty level do you play? And which level does your main have?
I ask because on normal and with level 30 or so that boss fight wasn't hard for me at all. In fact, it lasted only ten rounds or so and none of my party died once... So I think it highly depends on your strategy, your party setup and your gear.

I think you have the best party members with you for that fight. So I can only offer you some ideas to deal with:
1. If you haven't already done, buff up your party with Alexia before the fight. Use ctrl + u and give them favour of the devine, healing rain and stuff. Use arcane aegis and the shield from gwen too and all other stuff you might have in your arsenal.
2. If that is still not enough, find yourself some gear with unholy resistance because what I've read Lord Adrianus does that type of damage with his life drain. That will lessen the damage taken and also the amount he is healing himself.
3. Don't bother on debuffing him. I don't think that is of much use because this life drain seems to be a special move that is not affected by debuffs. Concentrate on dealing damage instead. Does your Gwen have AoE? Which elemental atunement did you choose? If you have heat wave or lightning bolt that should dispatch all the guards with the first shot, after that just gang on Adrianus with all you have.
4. Alexia has a skill that raises a fallen party member if it dies. It's called prophets thingy. Use that on your fellows early in the fight.
5. I don't know your agility stats. That is the most important stat for me. You say that Adrianus is to fast for you. Do you have dagger wasps adrenaline? That potion boosts your speed. I never used it, so I don't know how much it actually does.

Hope that helps. If you still can't beat him with that hints, you probably need to level a bit more or try to build a better equipment concept. I focused on magical crit chance and bonus fire damage with gwen and hell, she didn't need the other party members, she just one-shotted endire enemy parties with the first move...

Well, no, I don't think you need to. The difficulty should scale with level. I strongly believe you should be able to beat the final boss with that given strategy hints even with level 24.

you could always use the map if your lost. and Marc where you want to go on it.

its a place where a guard would pull a lever to raze the gate or lower it.

@Phoenix: Please, please, PLEASE tag your posts with spoiler warnings if they contain major giveaways about the game plot. I've reported your post to moderation—not that I think it's inappropriate, but just because I want to do everything possible to ensure that a new player doesn't stumble upon that bit of data.

@Chris: Regarding beating the final boss at your current level, it's definitely possible, though it will require some strategy and some luck. I think Honk gave you some pretty good pointers, and I do think that Dagger Wasp Adrenaline will be your friend if you're finding that he's too fast. Remember that potions, poisons, and buff skills can all be used out of combat to pump up your party before you go in. Also remember that if you absolutely can't beat him, you can always dial the difficulty down to easy.

@alexn94: Ha yeah Simeon and Alexia makes for some pretty funny head-canon, since they have that mutual antagonism thing going on. I wonder how long it will be before we see AHC fan fiction start springing up?

Hello. Please, one question. Can someone give me little hind how to complete pillgrim's progres in silvershade mine? Where is the shrine in this area? thanks.

@1442
Possible slight spoiler:
That lady in the north east part of town (can't remember her name), the one with the missing husband, also has a hint about the location.
Lol I actually searched for and found the sites myself the first time, and only later figured out there's a much easier way by following Joseph's advice above.

Or else!
Or else!
Or else!

I figured their should be an echo for dramatic effect...

@1446, lol!

hi,
Question here:
possible spoiler alert!
What does making alexia into a passifist achieve? What new abilities does she gain? How much bonus does it grant to healing?

Making her a pacifist is in my opinion not worth it. I managed just fine with her level of healing without it, and I got her to do enough damage to be useful; a friend took the pacifist route and regretted it as she was doing too little damage to be of much use in a fight.