Cave Vampire + Adaptive Grip (auto tool-switching off-hand item)

A neutral cave-dwelling vampire mob that becomes hostile only when provoked, or when you mine near it, and it drops a craftable off-handed item/tool that automatically switches to the best tool when mining. Mob ideas: Cave Vampire Spawns rarely in caves, lush caves, and deep dark areas. A new basic Mob. Neutral by default. It only becomes hostile if the player attacks it or starts mining/breaking blocks near it. It attacks with basic melee and has a chance to apply a short Weakness effect, and can damage durability of tools. When low on health, it transforms into a bat and tries to fly away to escape. In sunlight it also transforms into a bat and flees toward darkness instead of burning immediately. Drops: rotten flesh / bones / phantom membrane, and rarely a Vampire Fang. Item: Adaptive Grip Crafted with a Vampire Fang + redstone comparator + gold ingots Function: Place the Adaptive Grip in your off hand. When you starts mining or breaking any block, it automatically swaps the best available tool from your inventory or hotbar into your main hand. Results: Highest efficiency (material tier + Efficiency enchantment) Ability to properly harvest the block Help with accessibility with changing tools. Works with pickaxes, axes, shovels, hoes, shears, etc. After mining stops, it can either return the previous item or leave the selected tool equipped? Just an idea.