If you are capable of healing your cards, through items, actions, or character abilities, and Beast, Tragic Hero has damage on them at the start of your turn, you can let them attack and then heal them, allowing you to still benefit from the increased strength but keeping them healthy enough to stick around
Instead of directly stopping creatures from attacking you, it forces your opponents to make a tough choiceeither pay they 3 mana for each attacking creature, or they let you create a 3/3 Ogre token for each one
I also decided to exclude creatures that are better by being in a tribe
Such as Exsanguinate
If not for being 7 mana and three colors, this would be one of the biggest bombs in the set
If the ability stopped there, you'd have to pay seven mana to make this a 6/6