Most of the ATOM's are in data.kfs for any of the KB games including TL, AP, CW, WotN, I&F, and DS - I mentioned it
here.
I cover adding an ability to apply after a unit's attack it
here - this doesn't necessarily apply to what you're trying to do, but you need to understand how attacks / abilities are specified and then you're most likely going to have to go into the LUA code to determine what it is doing to see if there is anything specific to the Dragon Rider unit.
If you look at the above example, you will note that the Bone Dragon ATOM specifies the Bone Dragon's attacks via the "attacks=" line. You probably found this, but you also need to copy the actual ability section as well. Following the example in the linked post (although I don't show the code), there is a "poison_cloud" section of code later in the file that describes the "poison_cloud" attack. I will use this to mean the Dragon Rider Dive ability.
You will need to go into the dark_sprite_lake.atom file and add the name of the Dragon Rider Dive attack to the end of her "attacks=" line and then copy the "poison_cloud" (dive) attack ability code to her ATOM as well.
From here you need to find the LUA file that contains the code from the "script=" line of the ability. A GREP tool that searches contents of files is really helpful, although as a guess it is probably in an ADDON_*.LUA (probably special_attacks or unit_features) file. Once you find the function, you'll have to go through it and see what it is referencing from the Dragon Rider ATOM and determine if there is unique information that the Sprite ATOM lacks.
I'm guessing that there are unique animations that the Dragon Rider has that the Sprite doesn't - perhaps this is why the game locks up / crashes on you. As an alternate, you can look at the Giant's ability as you may find that is more generic and not as specific as the Dragon Rider code is.
Good luck - feel free to ask questions!
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