Invulnerability

Invulnerability is a buff that renders the target completely immune to all crowd control and damage, with the exception of direct HP removal. The only spell effects that apply to a unit under invulnerability are friendly-only movement spells like Chen's Test of Faith, even effects not stopped by magic immunity. Magic immunity applied to a friendly invulnerable unit will remove the buff, but the application of invulnerability will never remove magic immunity itself.

Many abilities that cause invulnerability also allow (phasing) no-clip, but this is not an inherent property of invulnerability itself.

Omniknight's Guardian Angel does not provide true invulnerability, but is in fact the bestowment of 1000 armor.