Hand looping (the act of taking a card out of a player's hand and getting rid of it) is incredibly powerful, and The Forceful Sentry has been banned for years
Some more prominent examples include "Dark Magical Circle", which provides disruption when "Dark Magician" is summoned, "Eternal Soul", which gives "Dark Magician" protection and can endlessly revive "Dark Magician" and trigger "Dark Magical Circle", "Dark Magic Attack", "Dark Burning Attack", "Dark Burning Magic", which are searchable blowout cards, and "Magicians' Combination", "Magician Navigation", and "Destined Rivals", which are situational negates
Either was, you get a payoff
It is accompanied by a much-coveted 10/10 grade, denoting its perfect condition
Once per turn, during your Main Phase: You can increase this card's Level by 1