Can you play Void Rush with 4 energy and use it to play a revealed Battering Ram (which costs 3 energy normally but reduces by 1 when you play a spell)?

Ruling: Yes, you can play Battering Ram this way for 2 energy total. When Void Rush resolves, you can put Battering Ram on the chain as pending. Void Rush then finishes resolving and counts as played. When you determine and pay costs for Battering Ram, Void Rush has already been played, so Battering Ram's cost reduction applies, making it cost 2 energy instead of 3.

Sequence:

• Play Void Rush and reveal cards including Battering Ram
• Choose to play Battering Ram, putting it on the chain as pending
• Void Rush finishes resolving (and is now considered "played")
• Determine total costs for Battering Ram (now 2 energy due to its reduction ability)
• Pay costs and finalize Battering Ram

Nuances:

• You can put a card on the chain as pending even if you don't currently have enough resources to pay for it, as long as you can pay when costs are actually determined
• There is currently no rule preventing you from pending a card you can't afford
• If you ultimately cannot pay costs when required, the game would rewind the playing process, but where the card goes is unclear since Void Rush doesn't banish cards first (unlike similar cards that received errata)