Des's Destructivity

Choose a willing creature that you can see within range. Until the spell ends, the target gains a boost to their Strength Ability Score equal to your Spell Casting Ability Modifier.

When the spell ends, the target's Ability Score is then reduced by the same amount, to a minimum of 1 (-5 Modifier), until after it's next turn. If the Score drops low enough, a target can be affected by over encumbrance.