Champion of the Path

If a cost to cast a spell includes revealing a card, that card remains revealed from the time the spell is announced until the time it leaves the stack.

If an Elemental you control that isn't a creature enters (probably because it's a kindred permanent with the Elemental subtype), Champion of the Path's second ability will still trigger. If that Elemental still isn't a creature when the ability resolves, the ability won't deal any damage.

If a card in your hand is already revealed (perhaps because it was revealed to pay a cost of a spell that's still on the stack or due to the effect of a card like Telepathy), you may reveal it again to pay the cost of another spell or ability that requires you to reveal a card from your hand.