2010-06-15 : All _Rise of the Eldrazi_ cards printed with totem armor are Auras with "enchant creature." But Umbra Mystic grants totem armor to Auras attached to any permanent you control, not just creatures. The ability works the same way even if the Aura is enchanting a land, an artifact, or any other permanent.

2010-06-15 : If a permanent you control would be destroyed, and it's enchanted by an Aura with totem armor, it doesn't matter who controls that Aura. The totem armor effect is mandatory. If that permanent is enchanted by multiple Auras, you choose which one is destroyed, regardless of who controls them.

2010-06-15 : Multiple instances of totem armor on the same Aura are redundant.

2010-06-15 : Say you control a permanent that's enchanted by an Aura you control, and that Aura is itself enchanted by an Aura. If the permanent would be destroyed, instead the first Aura is destroyed... but since that Aura would be destroyed, instead the second Aura is destroyed.

2010-06-15 : Umbra Mystic grants totem armor to Auras attached to permanents you control, regardless of who controls those Auras. Conversely, it doesn't grant totem armor to Auras you control that are attached to permanents controlled by other players.

2018-07-13 : If a permanent enchanted with an Aura that has totem armor has indestructible, lethal damage and effects that try to destroy it simply have no effect. Totem armor won't do anything because it won't have to.

2018-07-13 : If a permanent enchanted with an Aura that has totem armor would be destroyed by multiple state-based actions at the same time (most likely because a creature with deathtouch has dealt damage to that creature greater than or equal to its toughness) totem armor's effect will replace all of them and save the creature.

2018-07-13 : If a permanent you control is enchanted with multiple Auras that have totem armor, and the enchanted permanent would be destroyed, one of those Auras is destroyed instead — but only one of them. You choose which one because you control the enchanted permanent.

2018-07-13 : If a spell or ability (such as Akroma's Vengeance) would destroy both an Aura with totem armor and the permanent it's enchanting at the same time, totem armor's effect will save the enchanted permanent from being destroyed. Instead, the spell or ability will destroy the Aura in two different ways at the same time, but the result is the same as destroying it once.

2018-07-13 : If a spell or ability says that it would "destroy" a permanent enchanted with an Aura that has totem armor, that spell or ability is what causes the Aura to be destroyed instead. Totem armor doesn't destroy the Aura; rather, it changes the effects of the spell or ability. On the other hand, if a spell or ability deals lethal damage to a creature enchanted with an Aura that has totem armor, the game rules regarding lethal damage cause the Aura to be destroyed, not that spell or ability.

2018-07-13 : Totem armor has no effect if the enchanted permanent is put into a graveyard for any other reason, such as if it's sacrificed, if the "legend rule" applies to it, or if its toughness is 0 or less.

2018-07-13 : Totem armor's effect is applied no matter why the enchanted permanent would be destroyed: because it's been dealt lethal damage, or because it's being affected by an effect that says to "destroy" it (such as Putrefy). In either case, all damage is removed from the permanent and the Aura is destroyed instead.

2018-07-13 : Totem armor's effect is mandatory. If the enchanted permanent would be destroyed, you must remove all damage from it (if it has any) and destroy the Aura that has totem armor instead.

2018-07-13 : Totem armor's effect is not regeneration. Specifically, if totem armor's effect is applied, the enchanted permanent does not become tapped and is not removed from combat as a result. Effects that say the enchanted permanent can't be regenerated (as Putrefy does) won't prevent totem armor's effect from being applied.