As a construct rather than a fully organic being, Shayde had the ability to both emulate and actually join with other beings. His adventures with the Doctor occurred with him in one of three main identities. The "default", unitary Shayde that the Doctor's fifth self exclusively knew was followed by a Shayde who pretended to be a new incarnation of the Doctor. Shayde then joined with Fey Truscott-Sade to become "Feyde".