Originally Posted by
Ananan
When you heal a target with your Heal spell, the duration of the weakened soul debuff on the target is reduced by 2/4 sec, and when you cast Power Word: Shield on a target with your Renew active, the critical effect chance of the next tick of that Renew is increased by 35/70%.
That addition would make Renew a better tank healing tool and make you actually want to shield tanks as often as possible. It would make it slightly more useful to roll Renews and shields on more than one tank too, which is a good thing since Grace really messes with your ability to help out on a second tank. It would also make mastery slightly better for the more or less guaranteed Divine Aegis, and would make PW:S a little better as an oh-snap ability for a tank or anyone else that has a Renew up - shield him and you'll get a critting Renew tick in addition to the Borrowed Soul buff.
You could add the same effect to another talent if you want to keep Strength of Soul optional (it would still make Strength of Soul stronger) - Renewed Hope would fit well for example. That would probably be a neater design actually.