Question about multiple accounts

Is it okay to have multiple accounts? I am a new player doing the training battle and I suspect that one of the other players in the battle has multiple accounts. One of his accounts is on one team (the green team that currently has all the walls) and his other account is on the other (red) team. Well, he maneuvers his alternate account so that only his primary account can get any of the walls and the points - thereby moving his main account up in rank and he gets a higher reward at the end of the battle (pushing me down and there's nothing I can do about it). Is this legal?

According to the Terms and Conditions it is strictly forbidden to control multiple accounts.
Please report such findings in an ingame message to Admin.