Izzet League
The Izzet League is one of the ten Guilds of Ravnica. They are responsible for maintaining the civic works of the city: water supplies, sewers, heating, roads and so on. Which is probably not a good idea considering the guild's fickle attention span. Seriously, would you want a guild that needs a giant presumably dangerous spider making building's it's habitat in order for the building to be stable in charge of maintenance? When they're not busy doing this the magewrights perform magical experiments, often with spectacular (for good or ill) results. This does not really matter to the Izzet, because SCIENCE isn't about "WHY?"! It's about "WHY NOT?"!. Their child-like drive and curiousity, combined with their capriciousness and great intellect makes them unpredictable at best: they can jump from amicable professor to mad scientist in the blink of an eye.