If you control both Izzet Generatorium and Aether Refinery, be sure to order the effects so that you increase your energy production by one and then double it
It does hose companions, if something like Zirda, the Dawnwaker combo turns out to be good, but we likely have better cards there anyway
While Sephara may not be game-ending in its own right, coming down quickly and protecting your board of evasive creatures is nothing to scoff at
The legend rule still affects the token, though: You cant have two legendary permanents of the same name, or youll have to send one of them to the graveyard
Destroying all creatures is fairly common but as mentioned, mass land destruction is generally frowned upon in many play groups
This could even include an entire deck or an entire Cube all at once