How do I do devestator attacks?

[ILKA]

Hey, I sometimes have critical mass but have no idea how to do 'devestator attacks' can you help?
ty for reading and comment below :3

[Papaya]

You need to buy other attacks first to be able to buy the devastators:
for Groundspike Graveyard Devastator you need to buy Groundshatter first
for Tendril Barrage Devastator you need to buy Knuckle Shockwave first
for Critical Pain Devastator you need to buy Palm Slam first
Then the Devastators should be available to buy.
The buttons should be visible once you bought the Devastator upgrades.

[Retroburn]

I bought Palm Slam but I can't find Critical Pain Devastator anywhere on the Upgrades menu.

Help?