I did something similar to the sheeping one with threat. Basically, I wanted a threat indicator on the target frame instead of the player frame. Since I never need to know the mana of NPC's, and I never need to know the threat of PC's, I did this:
[~IsPlayer ? [PercentThreat < 75 ? [MaxThreat:White:Prepend([Threat]/)] ] ][~IsPlayer ? [PercentThreat >= 75 < 90 ? [MaxThreat:Yellow:Prepend([Threat]/)] ] ][~IsPlayer ? [PercentThreat >= 90 ? [MaxThreat:Red:Prepend([Threat]/)] ] ][IsPlayer ? ~HasNoMP ? FractionalMP]
What it will do show mana as a fraction (ie 5446/10013) if it's a player, or threat that changes color at certain percentages if it's a mob.