As a note, if the monk doesn't have at least an 16 (and that's absurdly low) after post-racial bonuses, it may be best to consider having a chat with the player and the DM saying "D&D doesn't like it when primary stats suck. What can we do to fix this?"
Feats:
- Superior Implement Proficiency: Accurate Dagger/Ki Focus
- Implement Expertise (Light Blades/Ki Focus)
- Deadly Draw (Get CA on enemies slid adjacent is better for centered breath, but there are a number of ways for stone-fist to take advantage of it)
- Nimble Blade (if you're going with Light blades. Great synergy with all of the above)
Items:
- Learning Weapon: gain a bonus to attack every time you miss the same enemy. Restricts the monk from using her AoEs, but when you're playing catch-up like this, most everything gets sacrificed.
General strategy:
- Combat Advantage, Combat Advantage, Combat Advantage. When you're not hitting, flanking or other CA granting means are your friend.
- Teamwork: Get the leader of the group to boost your attack modifer (she should be doing this anyways) or debuff enemy defenses.)
Well let's look at all of these one by one and we'll evaluate things as they come up.
The first thing you need to know though is that debuffs always stack unless they are coming form the same power. With that in mind let's look at at each power you've mentioned and inspect it individually.
The first one that we need to look at is the mark generated by the swordmage's aegis. All marks have the same debuff, -2 to hit any ally when they attack with a power that does not include you.
Psychic Lock inflicts a -2 penalty to the next attack roll. This stacks with the mark.
Mark of warding makes your mark a -3 instead of a -2. So attacking the target of your Aegis with a psychic power inflicts a total of -5 to attacks against your allies that don't include you, and a -2 against you, for their next attack.
Dishearten unaugmented against the target of your Aegis would have a net effect of inflicting a -7 penalty on his first attack against someone not you, -5 on subsequent attacks not you, -4 on the first attack vs you, and -2 on subsequent attacks against you during the round. Not your aegis is -4 on first attack, -2 on subsequent attacks during the round, regardless of target.
Phantasmal Killer has an identical effect against as above to your Aegis target.
The final case will have the same result as the debuffs from Dishearten do not stack. (the net -4 on first attack, and -2 on subsequent attacks do not add as they both come from the Dishearten power). Were you to find a different psionic psychic power that debuffs (say Mind Wipe) that would stack, though you would not benefit from psychic lock the second time.
Best Answer
Please keep in mind that anything that improves normal defenses, such as Improved Defenses feat, will also improve your Total Defense.
That said, here is a list of stuffs that specifically works for Total Defense:
Items seems to directly enhance your defense:
While feats tends to give your total defense some rider effects:
A few Class, Paragon Paths, and Epic Destinies grant additional effects like feats:
If you have can deal damage outside of standard action, such as aura, stance, minor action attacks, interrupts, conjurations, or summons with instinctive actions, and you stack them up, perhaps min-maxing Total Defense is workable, espcially if you are trying to solo.