Many of these creatures have powerful secondary abilities including creating additional creature tokens (Bladewing, Death Tyrant, Feldon, Kari Zev, Krenko, Mardu Strike leader), drain/life loss (Calculating Lich, Hellrider), direct damage (Combustible Gearhulk, Dreadhorde Butcher), anthem/buff effects for your army (Drana), card draw/free spells (Etali, Florian, Garna), additional combat step (Moraug), and many more
Well, yes, walls sort of count as defenders but actually no
Honorable Mentions This card is like a renewable 2 power creature that is very hard to kill
While I live far away, im definitely going back
Blue has plenty of cards like Aphetto Alchemist and Fatestitcher to untap this and draw multiple cards, and you can repurpose many of those cards into combo pieces that win the game