The latter is rarer than the former but you don't need this to win the game for you for it to be good either
Meanwhile, it's even more useless in Modern
Activated mana abilities may be played both when a player has priority and in process of casting a spell, activating an ability, resolving a spell or ability, if any such action requires a mana payment
4 Ancient Booster Energy Capsule is a Perfect Counter to Status Conditions Released in SV05: "Temporal Forces" When the format is as fast as it currently is, tool cards that raise HP are a valuable asset for players to have in their deck, and Ancient decks have access to one of the best HP-boosting tool cards in the game
What happens if they topdeck Distortion Strike
That means with instant spells, you can trigger the effect on your opponent's turn and copy all the spells already exiled with Arcane Bombardment