(2) this is a very weak argument even if you know that the opponent will try to mill you: using anti-mill cards is much better instead
From a mechanical standpoint, this card is also great for a Sakdos build
This isnt to say these are the only commanders you can run if you need an infect commander, stun counter commander, or a +1/+1 counters commander, or whatever
Marcy: From FFXIV, Raubahn is an Ala Mighan who serves the Sultana of Ul'dah, one of the three major city states in Eorzea, and is head of the Immortal Flames
It sees lots of Pauper play and even pops up in Legacy lists, usually ones running Death's Shadow
Plus, Cavalier of Flames ability to grant Haste to your Elementals on command makes Mass of Mysteries have a more immediate impact