Can't get esp changes to work

[Daiuuus]

So I loaded up an esm file (one from a mod) which has a spell in it.

I changed the spell and saved it as a NEW esp with skyrim, update and the mod esm as masters.

Put it at the end of my load order in MO but the changes don't show up ingame.

 

Or do dragons resist stuff even if you tick the Disallow Spell Absorption/Deflect and Ignore Resistance?