Oscilio, Scion of the Third Age

Instant -

, destroy a Lightning Flow you control: Discard a card and create a Ponder token. If an instant is discarded this way, you may play it this turn.

Rulings

From the Omens of the Third Age release notes

When Oscilio’s activated ability resolves, you will discard a card of your choice and create a Ponder token under your control. If the discarded card has the instant type at the time it is discarded, you may play it this turn from your graveyard.
When resolving Oscilio’s activated ability, if you discard a card with an instant activated ability but does not have the instant type in its type box, you will not satisfy the if-conditional effect and you won’t be able to play it this turn via this effect.
If a split-card is discarded to Oscilio’s activated ability and one side of the split card has the instant type, the card may be played as either side, even if the side doesn’t have the instant type. Split-cards with meld may be played on both sides. E.g. If Comet Storm||Shock is discarded, you may play it as Comet Storm, Comet Storm||Shock, or just Shock.
You may only play cards discarded to Oscilio’s activated ability at times you are otherwise allowed to. For example, if you discard a split card with action and instant typing, only the instant side could be played on an opponent’s turn (unless you can play the card as an instant through another effect).
If you cannot discard a card, you will still create a Ponder token.
If you cannot create a Ponder token, you will still discard a card and if it’s a card with the instant type, you may play it this turn.
When resolving Oscilio’s activated ability, there is no priority between any of the effects generated (e.g. discarding a card, creating a token).