One thing I keep running into, especially in those sprawling Slytherin!Harry or political!Harry fics, is how 'calls in all loans' flips the power dynamics completely. It's rarely about actual Galleons; it's the social debt, the favors owed, the ancient pacts everyone's forgotten about except the goblins or some crusty pureblood lord. When a character invokes that, the whole plot grinds to a halt and pivots. Suddenly, the conflict isn't Voldemort's next attack—it's about which 'ally' is going to betray you because their grandfather swore an oath.
I remember a specific fic where Hermione, of all people, uncovers a clause in some Founders-era charter after a deep dive in the Department of Mysteries. She essentially forces the Wizengamot to honor centuries of promised protections for Muggle-borns. The Death Eater plot just... dissolves? Because the institutional power she yanked into the open was way scarier than a bunch of terrorists. It can feel like a cheat code sometimes, honestly. Like the author wanted to avoid writing a big battle, so they pulled this bureaucratic deus ex machina. But when it's done with some set-up, showing the ledgers and the tense negotiations, it makes the wizarding world feel heavier, like it's weighed down by its own history. The fallout is usually more interesting than the call itself—watching alliances re-form like iron filings on a magnet.
My issue is when it makes Harry too powerful too fast. He finds a vault full of I.O.U.s from every major family and suddenly he's a puppet master. It strips away the underdog vibe that makes his story work. I prefer when the theme backfires, or when calling the loans reveals a deeper, nastier debt he now has to pay. Makes it less of a power fantasy and more of a trap.