Hello, to celebrate the almost 10-year anniversary of Undertale, I took a week to recreate the battle system in Construct 3.
LINK : dominosxpizza.itch.io/undertale-engine-construct3
I created a Template and made it so everyone should be able to use it with ease.
This template targets mostly beginner and intermediate users, as it could be used to create an Undertale fangame but also can be studied to learn how you could make a turn based rpg.
I think the construct community greatly lacks actual game template exemple that they could study.
To my knowledge, this is the most complete construct project shared out there.
(Include javalogs [F12] for easy debugging)
There is already multiple version:
V1 - Froggit Template -> basic template aimed for total beginners, is quite simple but lacks additional features. (Using 
SuperQuenouille6 sprite asset as base)
V1.1 - Toriel Template -> The most customized fight, is roughly the same as the one in the game. It includes cinematics, more advanced patterns, and a few custom things that the boss does.
V1.2 - Custom Sans Template -> A template done in a couple hours mostly used to make few changes to the engine.
V1.3 - Dummy Sans -> It resembles Sans but is more like a dummy enemy. Includes Toriel's bullet pattern too. The most up to date template.
I recommend using Dummy Sans, as it's the most basic fight but has a lot of additional features that ease creation. Furthermore, I will only update this one from now on.
Enjoy !
Also you can checkout my other template :
- Binding of isaac : dominosxpizza.itch.io/roguelike-template-construct
- Monopoly : dominosxpizza.itch.io/monopoly-template-construct3
- Deltarune : in progress …