[0.2.1] Non telegraphed unblockable attacks

There are some bosses with unblockable attacks with no red glow/sound cue, so it's hard to read the attacks.

The first that comes into mind it's Rattlecage, the Earthbreaker (first sekhema floor/crimson beach map). He has one slam that you can block/parry and another you can't, and it's very hard to notice if you can parry or not.

I think that if there is no red glow you could block it, like the mighty silverfist (act 3 jungle boss).