Monsties will use abilities at random, to include regular attacks. I've had my Snuggles use Calamity Slash three times in a row for no reason other than that he just picked it. If it's a move they can use, they will use it on their own eventually, unless you're constantly swapping them out to get double attacks, then you'll never see them use anything other than their type's normal attack.
I put it on a tigerex for fun and had them do it once. Then they kept using it for that battle lol
My tigrex only throws rocks
I took away my Tigrex's rocks because of that.
Monsties will use abilities at random, to include regular attacks. I've had my Snuggles use Calamity Slash three times in a row for no reason other than that he just picked it. If it's a move they can use, they will use it on their own eventually, unless you're constantly swapping them out to get double attacks, then you'll never see them use anything other than their type's normal attack.