Like Hellhounds,Cave Krakens have a high Slayer task weight,meaning they're a frequent assignment that you'll want to avoid. These monsters also can't be killed using melee or ranged combat,limiting you to RuneScape gold using a Trident of the Swamp or other single-target magic weapons. Their drop table is also lacking,with few valuable items to offset the slower kills. For these reasons,Cave Krakens are a prime candidate for your Block List,as they take considerable time to kill while offering minimal rewards.

Black Dragons
Black Dragons are another task that may seem like a good challenge,but ultimately is slow and inefficient. Not only do they have high hitpoints,but you'll need either an Anti-Dragonfire shield or an Antifire Potion to protect yourself from their devastating breath attack. While you can earn Dragon Bones for Prayer XP,they also have high defenses and require expensive equipment like the Dragon Hunter Lance for optimal kills. Plus,Duradel typically assigns only 10-20 of these dragons,which isn't ideal since you're aiming to kill large groups of monsters to maximize XP per task.

Greater Demons and Black Demons
Both Greater Demons and Black Demons should be blocked for similar reasons—high Slayer task weight,poor loot table,and inefficient XP. Duradel assigns large quantities of these monsters (typically 130-200),meaning you'll be stuck killing them for long stretches of time without gaining significant XP. Moreover,these tasks can be frustrating since you often have to compete with other players for kills,leading to slower kills and wasted time. While these demons can be useful for Ironman accounts due to their shared Demon classification (allowing for the use of the Slayer Helm),for most players,the inefficiency of these tasks makes them a poor choice for leveling Slayer.

Spiritual Creatures
Spiritual Creatures are found in the God Wars Dungeon (GWD),and while they don't have a high Slayer task weight,their slow kill times and poor loot make them a prime candidate for blocking. Not only are these monsters difficult to reach due to the God Wars Dungeon's hostile environment,but they also require specific God-Align gearto avoid being attacked by the other creatures in the area. For a player who wants to focus on efficient Slayer training,these creatures should be blocked,as they have one of the worst loot tables in the game. Unless you're specifically after Dragon Boots,there's little incentive to fight these creatures,and they'll be a permanent block for most players.

Steel Dragons
Steel Dragons are often considered a pain to deal with,and they fit the bill as a task you'll want to block. These dragons have high hitpoints,deal significant damage,and are weak to Earth spells,which were recently added through Project Rebalance,but that doesn't significantly speed up the kills. Moreover,Steel Dragons require frequent trips due to cheap RS gold the high cost of their dragonfire attacks and the time it takes to kill them. While their loot table can be slightly more rewarding than some others,the time spent and the danger involved make them inefficient for most players,and as such,they're a task that should definitely be blocked.