The first combat phase language makes it sound like you can only get a single extra hit, but combat damage to a player means that if you successfully damage all three opponents with creatures that are strong enough, this triggers separate instances
If your opponent has a bunch of creatures, he's just infesting the board, while sparing one creature
Therefore, you could pull out "Sudden Scare" as a way of quickly removing a dangerous character card from the board , and with it being put into the inkwell rather than being banished, players will not be able to return it to play
In-game description Behemoth is a Beastkin in Coerthas Central Highlands
Where its likely to suffer the most is in protracted battles with Ruby Decks that can clear your hard work with Be Prepared, or against Steel decks that can obliterate your characters more easily than you can theirs.
Given that the eventual payoff is potentially a lot of free cards, that sounds good in any blue deck