twilight sparkle<heavy breathing>: this guy’s a stubborn one…  
???: Hey Twilight, need a hand?  
Twilight <turns to where the speaker is>  
sunset shimmer: or two?  
connie maheswaran: friend, it’s time to show them our power!<jumps straight up>  
sunset: right! <uses magic to transform into unicorn form>  
<connie mounts unicorn sunset>  
connie: the rider…  
sunset: and mount…  
connie and sunset: ARE ONE!!! <rushes the enemy>  
connie: FINAL STRIKE: TORNADO BLADE!!!  
<explosion>  
connie: there is nothing…  
sunset: we cannot cut!
 
This was inspired by the special combination attack ‘tatsumaki zankantou’ from the super robot wars series of games.
 
there are multiple versions of this (becoming more elaborate than the last due to increases in console technology) but here’s a link of the latest video game version and the anime version