I wanted to be as orginal as possible though I am sure I pulled ideas that might not be 100% orginal.
The system I brainstormed would have Rets watching one of three new debuffs applied to the target by their special attacks and buff that their special attacks grant them. The buff allows the player to see the three debuffs. Here are the added buffs and debuffs:
Foresight: Allows the player to see the debuffs Divine Opening, Corruption, and Unholy Ground. Lasts 3 seconds. Refreshed by any of your special attacks.
Divine Opening: The crit chance of Crusader Strike and Divine Storm is increased by X% when used while this debuff is up.
Corruption: The damage of your Judgment spells and Exorcism are increased by X% when used while this debuff is up.
Unholy Ground: The duration and CD of your Consecration ability are reduced by 50%. The damaged is doubled. (8s Cons to 4 sec but still deals the same amount of damage.)
Your first special attack will put Foresight up on the yourself and one of the other three debuffs on your target. When you use a special attack the debuff changes. Since there are two specials that affect DO and Cor they both have a 40% chance to appear and since UG only has one spell it has a 20% chance.
I am not a numbercruncher. % modifers, damage out put, cooldowns, any number of things would need to be tweaked.
The system as simple as I can put it: No names or descriptions.
Your special abilities (CS, DS, Exo, Judg, and Concs) apply a buff to yourself that allow you to see one of three debuffs that rotate on the target as long as you use a special ability every three seconds. Each of these three debuffs buff one or more of you special attacks in some way. Spamming your abilities would mean wasted use of the debuffs and thus wasted DPS. I am not sure you could make a stable rotation out of this though.
I just went for something that would be more involved and not have us spamming abilites as they come off CD.
Flames, thoughts, other ideas, criticism, trolls expected!