If you run one of these commanders, you may need to have a Rule 0 discussion with your pod before you play your deck: Generally, these are commanders that most players don't want to play against at, say, Bracket 2, as Commander Format Panel member, Gavin Verhey puts it
Limited Cards Limited Right Arm of the Forbidden One X DARK Level 1 [ Spellcaster / Normal ] ATK 200 DEF 300 A forbidden right arm sealed by magic
This is similar to the capabilities of Scapegoat, but faster since it gives you two more monsters and is usable on your turn
"Harpie Channeler" has essentially become the main card in all Harpie-based decks, as she can Special Summon another Harpie monster from the Deck while also assisting in Xyz Summoning Rank 4s or 7s, while "Hysteric Sign" helps searching either "Elegant Egotist" or any Harpie cards you may need, depending on how you use it
If that card is an "Abyssal" Monster, summon it in face-up attack position, ignoring summoning conditions