The number on the bottom is the remaining durability of the Wall. YES, IT CAN BE DESTROYED. Rules: Dont change or delete ANYTHING. I MEAN IT. Add yourself, and only add yourself. Please don't make your attacks overpowered. The faster you attack, the less damage it should do. You should only make it really powerful if you attack every, say, 10 seconds.
Credits to @oxiti8 and @Multiverse42 for their original projects. 2020 update: Added Mario.