It lets you cheat out some massive creatures and powerful artifacts pretty early on
If the permanent somehow becomes tapped again before the next ability resolves, the next ability will untap it as well, and so on
So, as of Strixhaven , we're narrowing the focus a bit to create a new keyword mechanic: Ward [COST] (Whenever this permanent becomes the target of a spell or ability an opponent controls, counter it unless that player pays [COST].) The two most common forms you'll see are costing additional mana (in white, blue, and green) and costing additional life (in black and red)
(2018-01-19) Your new teammate must be someone not already in your game, although it can be someone who was once in your game but left
Rules will need to be clarified about whether this card can benefit from that effect as well, or if it only applies after the card is in play, as there is some confusion online already among players
Everyones comparing it to Venser, Shaper Savant, but it kind of reminds me of Cryptic Command with how versatile it is