[JASS] Looking for tutorial for jass spell

[i_am_cuul]

New to jass, did a bit a while ago and started learning about structs and i know theres a tutorial in the tutorials section that walks you through how to make a simple jass spell but are there any tutorials that can walk me through how to make a damage over time spell? (or is there a spell i can DL in the spells section thats simple and has lots of comments)