
Enchantment — Aura Curse
Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this token: Add one mana of any color.")

Cheap Aura that influences combat politics and forces attacks elsewhere.

Low-cost enchantment providing repeated incremental advantage like Curse's gold tokens.

Generates Treasure-like ramp tokens off opponents' actions.

Another political Curse rewarding attacks on the enchanted player.

Treasure-focused ramp synergizing with gold/treasure payoffs.

Explosive Treasure generation off opponents' artifacts/enchantments.

Politically encourages attacking enchanted player, rewarding attackers with tokens.

Forces directed attacks, similar political combat manipulation.
Curse of Opulence's triggered ability resolves after attackers have been declared. Any costs to attack must have already been paid before the attacking player creates the Gold.
Each Curse's ability triggers only once, no matter how many creatures are attacking the enchanted player.
A player is attacking another player if they control a creature that's attacking that player. If no creatures are attacking the enchanted player as a Curse's ability resolves (most likely because they've left the battlefield), only the Curse's controller performs its actions.
The triggered ability of these Curses won't trigger if only a planeswalker controlled by the enchanted player is attacked.
If you enchant yourself with one of these Curses, you'll get its effects whenever another player attacks you.