The bard paragon path Life Singer is based on a cool and original concept: a pacifist character that tries to solve conflicts without resorting to violence. It is an unfortunate event that, because of an overpowered feature, the path ends up as a very tempting option for bloodthirsty killers...
The controversial path feature is called Serene Will, and it allows rerolling attacks against will. There is a small bonus thrown in if the attacks in question don’t deal damage, but otherwise nothing prevents you from going to town with Will attacks, violent or not. I have already discussed how absurd a reroll-granting feature is, so I’ll just say that it is really absurd, and in need of fixing.
It is not impossible to balance the ability to reroll most of your attacks, but it does require adding severe restrictions or some kind of drawback to compensate. Limiting the effect to attacks against will is hardly enough. A natural and flavorful solution would be to have it work only on non-damaging attacks but, alas, these are pretty scarce for the bard class, so we would be rendering the path unplayable, outside of weird multiclass builds. Still, the idea had potential, so I came up with this:
Serene Will (16th level): Before you use an attack power, you can choose to have it deal no damage. If you do, you can reroll missed attack rolls targeting Will made as part of that attack, and must use the second results.
There might be an uninteded interaction that breaks this rule in half, but I think this could work just fine. The rerolling is now tied to behaving like a proper pacifist, which is manageable but hugely restricting. On the other hand, it also grants the ability of using any power for non-damaging purposes, opening up a whole lot of combinations. Note that any area attack will lose its damage against all targets this way, so there should be no obvious way to exploit this to prevent hurting allies in the middle of a fireball.
A fix for a different issue
Though not a critical problem, the level 20 daily, soothing song, is worded so that the enemies you knock unconscious can’t be coup de grace’d by your allies - but nothing prevents YOU from slaying them, which is wrong on so many levels. I’d change the Hit line for the following:
Hit: The target falls unconscious (save ends). Each ally in the burst can spend a healing surge. If you or ally attacks an affected target, the target immediately awakens. The attacking character does not have combat advantage against the target for that attack and cannot make a coup de grace attack against it.