The first thing that leaps out at me about orthons—described in Mordenkainen’s Tome of Foes as “infernal bounty hunters”—is that they’re proficient in all of the “big three” saving throws: Dexterity, Constitution and Wisdom. I run across monsters with two of these three saving throw proficiencies fairly often, especially when looking at monsters with higher challenge ratings, but I’m not sure when I last saw a monster with all three of them. Put these together with Magic Resistance, and the takeaway is that orthons are utterly unafraid of spellcasters. They don’t even go out of their way to take spellcasters out quickly. They’re indifferent to them, which, if anything, is scarier.
Orthons are called into play when an archdevil wants an enemy dealt with, dead or alive. They’re brutes, with extraordinary Strength and Constitution, but their Dexterity and mental abilities are far from shabby. They’re expert in Perception, Stealth and Survival—consummate ambush attackers. They’re immune to fire and poison, can’t be charmed, never tire, and are resistant to cold and to physical damage from nonmagical, nonsilvered weapons.
They have 120 feet of darkvision and 30 feet of truesight, so they prefer strongly to attack at night or in a darkened location. But even in daylight, they have the Invisibility Field feature, which lets them turn invisible as a bonus action! An orthon will always use this feature before launching an attack in anything less than total darkness—and even in darkness, if its target has darkvision. Thus, it will always make its first attack with unseen-attacker advantage. (more…)