"Wherever the strong would harm the weak, I will be there."
—Ajani Goldmane

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

"You will take nothing, Klaw. Your plunder of Wakanda ends here!"
—T'Challa, the Black Panther

Secret Lair Drop

"Another beautiful day in the most dangerous place in the world."
—Nick Valentine

Fallout

A planeswalker with indestructible still loses loyalty counters as it's dealt damage and will still be put into its owner's graveyard if its loyalty reaches 0.

The set of permanents affected by Heroic Intervention is determined as the spell resolves. Permanents you begin to control later in the turn won't gain hexproof and indestructible.

A battle with indestructible still loses defense counters as it's dealt damage. If it's a Siege, it will still be exiled when the last defense counter is removed from it, and its controller may still cast it transformed without paying its mana cost.