Before getting to Bannerman Hill, you must go through here first. This area has 3 sets of fight, which increase in difficulty one after the other. These fights consist of Ministry of Justice Elite Guards, who do not do much damage per hit, but attack many more times per round than the normal soldier.
You will also encounter Ministry of Justice Conjurers, who cast devastating spells that will stun you and damage you as well.
What's more, these 2 soldiers can use the Unison Ability, Sym Link, which will allow them to do more damage to you. As a little hint, when you see them form a Sym Link, if you damage the caster for at least 30 points of damage, the link will break.
Here is a breakdown at what you should do, depending on who you brought with you:
At this point, unless you have somehow rushed through everything without fighting anyone, you should be at least level 5. This means that she will be able to summon 2 Medium Aqua Constituents. The first thing to do is explicitly summon them.
Since her summons can use Elicit, they should be able to keep the hate of the guards off of Aramus and her, allowing you to freely hit them.
When you start to fight the conjurers, ALWAYS take out the conjurers first. They use an AoE spell called blizzard, but the summons should be immune to this, so don't worry if they go after the summons. Just concentrate on taking them out first. The best thing to do is to use Illuminate on any conjurer you see. The conurers always start with a spell that can stun your entire party, so you want to stop them from doing that. If you are lucky, you may be able to kill them before the effects of Illuminate run out.
Finally, if you have gained over 100 BOB points with her, try to stay as close to her as possible, to get the effects of regeneration.
The overarching goal here is to keep ALL enemies away from Challseus. Yes, he will try to flee when they get too close, but all this means is that he isn't actually damaging them. Now, when you start ANY fight, always activate Inferno. This will deal heavy fire damage to anyone within range, and will continue to eat up HP's from them as the fight goes on. If you cannot keep the hate on you through the use of Elicit, don't hesitate to use Illuminate, so they don't start to run after Challseus.
Once you start running into conjurers,