LegendConductor

I'm not sure about the Rainboom itself, and Death Battle messed up when they claimed it busted solid rock. It was a Geode, meaning it has a hollow middle lined with crystal, which is much easier to break than most solid rocks.I do know that if Rainbow dash was to kick someone while flying at the calculated Mach 10 after her Rainboom, she would Impart 2.3 Mega-tonnes onto whatever she hit. I just used the calculation for kinetic energy to joules conversion formula J=1/2M*V^2. Assuming she weighs 168 pounds (Calcs can be found here https://scifi.stackexchange.com/questions/147000/what-is-the-weight-of-ponies-of-the-my-little-pony-universe) and is moving at mach 10, She would deliver 988251600 Joules of energy, which can then be converted to Mega-tonnes resulting in 2.3619780114723E-7 Mt of kinetic energy being imparted on her poor poor target.

You say using equations and physics is pointless because it's a carton, but you then go on to say lightning isn't impressive because it looks slow basing that opinion off of the same base values used to calculate speed, just not using numbers? And even if they could dodge lightning, (Which Rainbow Dash definitely can.) so what? In a show where Unicorns shoot beams of light, which we have to assume are travailing close to, if not SoL, Dodging lightning wouldn't really help. Light is much faster than lightning, like, by a huge margin, so it wouldn't be unbeatable. She has to be flying at least past Mach 1 before entering the Rainboom state, because she already has a Mach cone around her every time she does it. Mach cones don't form unless you're already moving faster than sound, so to say it's just a regular Sonic Boom with pretty colors doesn't add up. Showrunners have given no statement, so we have to go off of what we know and see.