Bogles' Slippery Bogle and Gladecover Scout have hexproof, making single-target removal like Snuff Out and Cast Down useless against the key enchanted threat, so cut Snuff Out for Arms of Hadar. It targets the player rather than the creatures, so it gets around hexproof and gives all of their creatures -2/-2. It can kill an unprotected Bogle or Scout before it gets loaded with auras. Keep removal that doesn't target creatures, since hexproof shuts down anything that does; your best plan is racing with card advantage and countering their key auras (Ethereal Armor, Ancestral Mask, Armadillo Cloak) with Counterspell before they resolve. Thraben Charm's damage mode scales off your own creature count, which is usually low, so it's not a reliable answer, but it can still hit a non-hexproof threat if drawn.