Monkey King’s clones copy the permanent Aghanim’s Scepter buff, due to providing spell upgrades, attack damage and spell amplification.

They should copy Moonshard as well, because it provides a night vision component that they would otherwise be lacking.

They should also copy the Royal Jelly buff, because it is another item-based permanent buff and all temporary hero-based summons (illusions, tempest doubles, etc) usually copy them.