Forum:Beast Riser rulings

I may be jumping the gun, here, but I need some ruling clarification for Beast Riser, since the card itself gives no indication to them:

1. Does the ATK boost last for as long as the monster remains face-up on the field, or does it go away at the end of the turn?

2. Can I use it during the opponent's turn, or must I only use it during my turn?