If an effect refers to a "[subtype] card," it refers only to a card that has that subtype. For example, Glen Elendra's Answer creates a Faerie token and features a Faerie in its art, but it isn't a Faerie card.

If Champion of the Path is countered or otherwise fails to resolve, the beheld card will remain in exile indefinitely.

If the Elemental that caused Champion of the Path's second ability to trigger is no longer on the battlefield when that ability resolves, use that Elemental's power as it last existed on the battlefield to determine how much damage is dealt.

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.

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 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.