Just remember though, card rarity and condition is very important in terms of value
If you want the pirate theme here, Academy Manufactor will pull yeomans duty
Pokemon Medicham Power Keepers Uncommon Market Price $1.23 $0.25 Median $1.99 Normal $1.23 Reverse Holofoil $13.90 Prices from TCGplayer, updated 11 hours ago
A 5/4 for 6 generic mana is actually fair, but that's no longer good enough for players, even in Limited
Blackmail Target player reveals three cards from their hand and you choose one of them for that player to discard Duress Target opponent reveals their hand and you choose a noncreature, nonland card for that player to discard Encroach Target player reveals their hand and you choose a nonbasic land card for that player to discard (can hit non-basic lands!!) Grief A 3/2 creature with Evoke (Evoke cost is exile a black card from your hand) When it enters the battlefield, target opponent reveals their hand and you choose a nonland card for that player to discard Inquisition of Kozilek Target player reveals their hand and you choose a nonland card from it with mana value 3 or less for that player to discard Mires Toll Target player reveals a number of cards from their hand equal to the number of Swamps you control and you choose one of them for that player to discard Thoughtseize Target player reveals their hand and you choose a nonland card for that player to discard you lose 2 life Unmask Exile a black card from your hand rather than pay this spells mana cost Target player reveals their hand and you choose a nonland card for that player to discard There are tons and tons of Black discard effects in MTG
Blind Obedience sees play in many archetypes, from bleeder decks to lifegain and stax/prison decks
