"Attacks are directed at an opposing team." as per
Epic Card Game Rule Book wrote:
Hydra (equal number of players on each team)
A team of players shares the same turn. Each player has their own decks, discard piles, champions, and gold, but they share a health total that begins at 30 times the number of players on the team. Attacks are directed at an opposing team. A player’s champions may attack and block in groups with teammates’ champions.