I used nagaling with a predator spell to do 2 damage against a minion with elusive and the spell did nothing.
As far i remember the elusive prevent being targeted by spell and hero powers, but battlecries should work. In this case the battecrey is “cast a spell”, but as far as i remember this thing works a couple expansions ago.
Did the battlecry let you choose the elusive minion as a target?
The mechanic has been changed a while ago to deny the ability to target elusive and stealthed minion with such effects. They are now never legal targets. If you can target them through an indirect selection (nagaling, zentimo…) , they will instead target another minion that is actually a legal target and, if none, they will fizzle
it does. There is no problem targeting elusive minions with a battlecry. The issue is the spell is negated.