How would you deal with an enemy that had a million health?
I have a 200 million power token to show off but I’m not sure how to include an image.
I would say one cast of murder precharged and disabled while it’s AIs turn is my prefered way to deal with shenanigans like that.
And careful when doing such stuff.
The maximum integer value for power is 2^31 -1 = 2,147,483,647. If you exceed that, your creature becomes dead weight.
Use Etrata or Hour of Glory to instantly win 
But seriously, 1 million power is nuts. Best I’ve gotten is a few thousand before I got bored and stopped the loop.
This is my deck (I call it “One Punch Man” in my favorite decks)
Planeswalker Karn
Deploy the gate watch
God eternal Rhonas
Repeated reverberation
Star field of nix
Sphinxes decree
Settle the wreckage
High alert
Insidious will
Strategic planning
Talent of the Telepath
You just hide behind starfield shenanigans until you have 6 deploys or reverberations in your hand then you double the karn tokens power 18 times and bam millions of damage in about 10 minutes.
Anyone else have any ideas for doing a million damage in a timely manner?
For a million damage, you need something that grows damage insanely. I’d use a graveyard fun deck, either with vizier of many faces (brought them up to around 8k damage in a normal loop) or beacon bolt. Or both.