Hmmmm. When asked the question, “What’s the best way to get to Ravnica?” how would you answer? Maybe drive? Or take a boat? Or planeswalk, if you’re a planeswalker, however that works. Seems reasonable.
If you’re Nicol Bolas, you use the Planar Bridge. It opens a portal between planes, one that conveniently is big enough to transport your zombie army. And then you open that portal…on top of the Guildpact Chamber?
That’s the freakin’ civic center, Bolas! You just wrecked the civic center. There are civilians there. The property damage is immense. Come on, man. Why not find a big field outside the city or something?
Spoilers, guys: Bolas doesn’t care about any of that. He wrecked the Guildpact Chamber on purpose. Welcome to Ravnica.