Garens passive, and the new masteries
I would like to preface this by saying I hate Garen, like I really don't like to play with him or against him, so when I say that he needs this changed, I am saying it with a heavy heart. I noticed this whilst playing Garen in an ARAM match. Taking the mastery "Bond of Stone" makes Garen's passive useless.
The new keystone mastery "Bond of Stone" which allows you to take 8% of the damage dealt to allies, is probably the best team oriented mastery on the resolve (defensive) tree, and unfortunately works really badly with Garen's passive "Perseverance". When any ally on your team in a decently large radius takes damage from literally anything, this mastery kicks in, and you take a part of the damage and your passive stops.
So if you have disengaged after being chunked out a bit, and you want to wait to the side of the contested tower or objective and heal up, if a single ally takes a single point of damage, then you have to wait another 8 seconds before the heal can begin again.
Stopping this mastery damage from counting, and allowing Garen's passive to continue would make a lot more sense, because then once again, it is the Garen who needs to avoid poke whilst healing, not his entire team, and in a team fight or even a small skirmish, the passive will still fall off as soon as he take damage, just like it used to.
Tl dr; Until rito decide to remove this interaction the keystone mastery "Bond of Stone" will actually be a detriment to you whilst playing Garen.