Generally, its trivially easy to make sure this wont backfire, and even if it does, theyre now spending 2 mana on your turn for a spell that they just watched you cast for 1 mana
Here, we see that Excadrills Iron Head onto Sylveon does between 198 and 234 damage, or between 98% and 115.8% of Sylveons HP-- so it might not always knock Sylveon out
It features some of the most iconic legends in the game, and for many, thats a huge draw
And while I normally focus on Commander, its pretty much a free-for-all today
Other monsters you control cannot attack, also if you have any number of "Blue-Eyes" monster(s) in your GY, the equipped monster can attack up to that number of times during each Battle Phase