Building a monster for d&d 5e

[TheEcho]

Hey everyone. This is my first post so please let me know if this materials belongs in a different section of the forums.
For a current campaign with 6 lvl 6 players I am planning a horror style session and wanted to include the monster from the movie spectral(on Netflix).
I have been starting wth the invisible stalker and the primary change is making it hit harder (I am trying to press the group to avoid a direct conflict and eliminate some of the many red shirts they have collected on their journey) as well as some additionl ways that the creatures can be repelled and detected like in the movie. It will also be stopped by magical wood (sylvanwood) which several party members have weapons and shields of.
I guess my main question is how hard it should hit? I was thinking 2d8+4(or 6) per slam. This gives the ability to take out red shirts and hurt the party in a more horror / hit and run style.

Thank you for any responses!

[hymer]

Welcome! This probably does belong in the 5e subforum. You can report your first post, and a moderator will take a look.

Anyway, I don't know if you know this, but how hard it hits affects the creature's Challenge rating, and thus which PCs it is likely to be suited for. Page 273-274 in the DMG has guidelines on creating and modifying monsters.

Since your primary aim seems to be killing specific NPCs, letting us know what sort of defences, particularly hit points, these guys have seems pertinent to the discussion. If you want to add to the horror element, you can have it deal damage with a delayed component, such as poison. Then some NPCs will get to fully appreciate the horror of dying, and could make for a nice roleplaying moment for some. It might also give the PCs a chance to save particularly beloved NPCs, adding to the tension.

[TheEcho]

Thanks for the reply! I will have to look at the different forums more closely before posting next time.
I had not actually known about the section of the DMG that helps with modifying monsters. Previously I have just made the monsters do more damage or have more health, primarily because the party is normally between 6 and 8 players so they needed some heftier targets even at lower levels.

The party normally consists of 2 paladins, a cleric, a wizard, a sorcerer, a druid. When everyone can make it there is also a rogue and another paladin. Their health varies wildly, with a paladin having the lowest in the party but they also have a variety of magical gear to help them after about 19 sessions.

Most of the NPCs are part of an organization so they all have rogue/fighter abilities and around 30 Hit points. A few of them are veterans which will have more advanced skills and double the hit points. They don't have much in terms of magical weapons but lots of tools and heavy armor is available to them.

However, I really like your idea of ongoing damage to emphasize the horror component. Something I had been thinking is that if instead of increasing the damage overall was to make is Necrotic damage so health couldn't be healed initially and if this was followed by a poison affect it could create a ticking clock for the party.