Adding 35% to armor/defense with 1 buff is definitely overpowered. Of course, these will be popular buffs and make EOC players lots of purple dots selling them.
But then again, when you add "win button" buffs like dispel curse it does not surprise me that you are unsure about 35% being over powered. I was thinking your option 2 would work fine. It will still add a nice stat bonus.
Another solution could be to make it PVE. Its going to take so many calculations to figure out if you have a good chance to win in pvp nowadays that its not going to be worth it.
Giving it a bit more thought, Smashing Hammers balanced out the Severe Condition + Ageless + Sanctuary + Terrorize combo. If you throw in more buffs that boost armor, that throws things off balance.
Similarly, Keen Edge balances out Constitution + Nightmare Visage + Flinch + Barricades. If you throw in more buffs that boost defense, that also throws things off balance.