PROJECT: League of Legends on Tablet (Version 1) *Need Help*

Hey guys, so recently I bought a Mac Mini and forgot to buy a monitor, so I heard you could get apps to display your Mac on a iPad, but none were edible to make it without being laggy, so I bought and Thunderbolt to HDMI cable and tried to display my Mac on my iPad but it didn't work, and instead displayed my iPad on my Mac, any help? Thanks!

Do it for a cigar ;)