you can use a termination punch as a natural weapon. Your unarmed strike does 1d6 bludgeoning damage plus 1d4 lightning damage.

You do not require food air or water. You have no soul and cannot be healed by normal healing magic such as cure wounds, although mending heals you by 2d6. A creature can spend 3 hours repairing you and giving you the benefits of a long rest, but the creature gains 1 level of exhaustion. Your creature type is construct. You cannot be poisoned and have immunity to psychic and poison damage.

If you see a monstrosity, you immediately identify it as such (so if a doppelganger were to disguise themself, you could tell they were a monstrosity but no more than that). You must make a dc 18 wisdom saving throw or attempt to destroy that creature at all costs. You can choose to willingly fail this saving throw. You use all of your movement and actions attempting to destroy that creature. If the creature has a challenge rating higher than your level, you don’t make the saving throw, but count as aggressive towards the creature either way. You must retake the saving throw every tome you lay eyes opon the creature. You do 5 more damage to monstrosities.

you can use a eye beam attack once before a long rest. The beam is 70 feet long and 10 feet wide. Every creature in that radius must make a dc 13 dexterity saving throw. They take 3d6 force damage+ your constitution modifier on a failed save, and half that on a successful one.

you can never gain proficiency in persuasion, but gain proficiency in intimidation.

sentinels are driven by one thing and one thing alone. To destroy all monstrosities no matter if they are good or evil. All monstrosities will burn at the hands of the sentinels. They are lawful neutral most often, because they do not discern between good or evil. If it’s a monstrosity, it must die, no matter if it harms or helps.

sentinels are very tall standing at 14 feet tall. They are also made of super advanced tech and weigh over 5000 pounds on average. Your size class is large.

on the bottom of your feet are thrusters. You have 200 units of fuel in you. You can spend an action powering on your thrusters. All creatures within 5 feet of you take 6 fire damage. You can then fly on your next turn. You can fly a maximum of 200 feet a turn. To fly you burn units of fuel 5 fuel=5 feet of flying. You can defend to the ground at any point. All creatures within 5 feet of the spot you descend to a take 5 fire damage. You can run out in midair though so be careful!

You do not sleep, but spend 8 hours in an inactive state. You can normally see and hear like normal but you are inactive. You regain all expended fuel after a long rest.

you are mighty, but soulless. You have +2 to strength and constitution but -2 to charisma.

you have advantage on nature and insight rolls when dealing with monstrosities.

Due to sentinels being machines, they never age.

you have 50 feet of Darkvision. In exchange for the range being shorter, you can distinguish color.

you can speak, read and write common and 2 other languages of your choice.