9/10 The scenario that goes like this
I master of phyrexia now is going to domaria where the enemy is.
This will make me vulnerable for no reason at all.
It will also take a shit ton of energy and I don't even need to do it because my minions are already winning the war.
If I am there I will create more minions for no reason at all because I already have more then enough and I am winning anyway.
result he gets killed, his minions lose hope, the world off phyrexia collapse.