prophet of kruphix

[particle]

if i have {prophet of kruphix} out, can i bestow at instant speed?

[Mattao19]

It is still a creature card so for a quick answer I'm going with Yes. BUT, still wait for somebody to confirm

[Arbitratur]

if i have {prophet of kruphix} out, can i bestow at instant speed?

here is the answer:

Yes. The explanation comes straight from the Theros Release Notes:
At the time you're casting it, it's a creature card.

You don't choose whether the spell is going to be an Aura spell or not until the spell is already on the stack. Abilities that affect when you can cast a spell, such as flash, will apply to the creature card in whatever zone you're casting it from. For example, an effect that said you can cast creature spells as though they have flash will allow you to cast a creature card with bestow as an Aura spell anytime you could cast an instant.

702.102. Bestow

702.102a Bestow represents two static abilities, one that functions while the card with bestow is on the stack and another that functions both while it's on the stack and while it's on the battlefield. "Bestow [cost]" means "You may cast this card by paying [cost] rather than its mana cost." and "If you chose to pay this spell's bestow cost, it becomes an Aura enchantment and gains enchant creature. These effects last until one of two things happens: this spell has an illegal target as it resolves or the permanent this spell becomes, becomes unattached." Paying a card's bestow cost follows the rules for paying alternative costs in rules 601.2b and 601.2e–g.

[Bop]

On a somewhat related note... Would {Hypersonic Dragon} allow you use the ability on  {Whip of Erebos} at Flash speed? I want it to be so... But I've been told it doesn't work that way and I'm not quite sure why.

EDIT: nvm, read the ruling on the dragon. :(