With Summoning Curse on the field, each time a monster is special summoned, the owner must banish a card from their hand
Or, as is often the case, a game loss
They held up better to the shuffle test and seem like a fairly good budget option for sleeving
This is because, with the exception of "Darklord Descent", they all share the cost of sending a "Darklord" monster (or any Fairy monster in the case of "Fallen Angel in Darkness") from the user's hand or field, causing the player to lose hand/field advantage (whereas "Darklord Descent" requires half of the player's LP to be activated, causing the risk of being unable to use the copying effect of the "Darklord" monsters)
You'll also find a stack of booster packs from different Pokemon TCG expansions
You can only regenerate creatures on the battlefield to stop them from being destroyed