This last one can be very useful, as it allows yourself to Special Summon one more "Noble Knight" monster from your hand.
Use this card in a "Noble Knight" Deck with "Imperial Iron Wall", so that this card won't be banished when used for a Synchro Summon, while having the potential to negatively impact your opponent's banishing options.
Two copies of this card or "Level Eater" in Graveyard can easily make a Rank 1 Xyz Monster.
Equip "Noble Knight Medraut" with "Noble Arms" to Special Summon "Ignoble Knight of Black Laundsallyn", then equip that "Noble Arms" to "Medraut" again. Now two copies of this card can be Special Summoned or "Level Eater" by reducing the Level of "Medraut" and "Black Laundsallyn".