Interception redirects attack from an ally to you at the cost of a minor action. You get a +20 resistance and -20 defense when intercepting. Sentinels only use a quick action.
Any combatant can be affected by multiple marks, but only one mark of each type.
Charm’s effect is executed before you take your turn, but your SP recovers at the start of your turn. If you spent all your SP previous turn you will only be able to use a basic attack.
When targeting an enemy with an ailment that is already in effect you don’t need to make an attack roll, the ailment automatically hits and extends the duration.