I'm not really sure what I'm looking for out of a white 2-drop spell. The source cube played Immolating Glare, which destroys any attacking creature. Puncturing Light trades the any-creature clause for the ability to damage attacking or blocking creatures. I think this is on average a little more powerful; it can help clear out most 0/X blockers when swinging with a 1/1 but comes at a pretty big cost for such a proactive play.

Some considerations I have on hand:

Swift Response: Destroys a tapped creature. Right now nothing in the cube has vigilance and we don't have a tapper, so this is essentially destroying an attacking creature but with some timing freedom. It does remove the offensive utility of Puncturing Light though.

Slash of Talons: Deals 2 damage to an attacking or blocking creature. This becomes a great defensive one drop on the draw without enabling blowouts on the play. My hesitation here is a color-pie one; white's defense on the play is primarily lifegain, not direct damage. The gap here between one and two mana is really big.

Swords to Plowshares: Interesting that it can answer any 0/X blocker on the play and lead to a win, but answering a 1/1 on the play with your own 1/1 out gives enough life to cancel out your attack. I thought this would be overpowered but maybe it works as aggressive tech against defensive decks?

Condemn: Poor man's Swords is also pretty interesting as a purely defensive card. What's extra interesting is that it can buy you time from attacking creatures (which are likely to have low toughness) but you can also target your own creature for lifegain. Imagine comboing this with an attacking Aegis Turtle to gain 5 life (at the cost of 2 cards!).

Awe Strike: Worse Healing Grace. When target creature deals damage to you, heal that amount instead. I'd rather include cards with different complementary effects than worse cards for redundancy's sake. The cube's only 54 cards, and mulligans are already wildly powerful in 15 card decks.

Warning: Even worse Awe Strike, a one-creature fog isn't where we want to be.

Oppressive Rays/etc.: Disabling attacking is nice but disabling blocking might be too powerful for white on the play. I'm pretty concerned about adding too many one drops that can enable a turn 1 survival and a turn 2 kill.

Off Balance: Target creature can't attack or block this turn. I'd love this effect if it was only "can't attack" though that might be too weak an effect for a card.

Chaplain's Blessing: I don't really think white needs more lifegain toys, especially not this efficient.

Some cards I don't currently have but would consider:

Kami of False Hope: A 1/1 that can sac itself on the play in response to 2-drop removal and prevent combat damage that turn seems really really neat for white. White is king of 1/1's with utility in this cube.