Yes, you can ignore it if you have lethal on the board--it's not designed as a directly defensive card, but as a TEMPO card. Once it hits the field coming from a well-designed deck, one of two things happens--either you were in a position to kill them before the card hit and you do so, or your left facing a clock against a deck that's likely full of efficient answers that's going to soon outstrip your threats and bury you in CA.And flavorwise, the design is remarkable...no, it doesn't have direct self-defense ability-wise, but comes down with loyalty enough to make it hard to beat down (and thus offering the potential of pseudo-lifegain) and with onstensibly a 3-turn clock to locking the opponent out of burn and removal. I HATE UW Control with a purple passion, but I have to applaud the design team on what is unquestionably a beautifully-designed tempo enabler.
Personally, I want to see what this can do for black-based Esper...dropping new Sidisi to roadblock Rhinos and other ground forces and then tutor up Narset/Dig/Cruise to start chaining draw spells full of answers seems pretty damned fun...