It gives your opponent a choice: let your spell be countered, or they can pay 5 life to keep it from being countered
Raise its power up then just sac itself
One great thing about the card disadvantage Mox in these lists is that you are able to gain so much value out of cheating in a fatty that you are pretty happy to give up cards to get there in the form of Vampiric Tutor, Faithless Looting, the Mox etc
As your commander, you will likely get multiple chances to cast Maelstrom Wanderer, giving you tons of cascade triggers
Kamahl, for example, went from being a vicious pit fighter to being a sage leader
An infinitely large Boo kills one player, but its easy enough for Naya to find three trampling creatures or just enough creatures to overwhelm your opponents and get around their blockers