Prince Valanar has all of the effects—if you build your deck right
With cards like Reno Jackson rotated out of Standard Hearthstone, macro deckbuilding rule cards has kind of gone out of fashion in the game. Knights of the Frozen Throne is trying to bring them back.
The final of a trio of cards in this vein was revealed during a card reveal livestream by game designer Matt Place and personality Sean "Day9" Plott.
If you avoid any other four drop minions in your deck, this card becomes very powerful.
Lifesteal and Taunt are a great combination, giving you a great effective life boost. Whether or not a deck without four drops can be good remains to be seen, but the Prince decks could be a lot of fun. Four mana 4/4 doesn't sound good, but when you stack a pair of very complementary effects it could be a great game winner in the mid game.