Equipped creature gets +3/+0. As long as equipped creature is a Human, it has lifelink. Equip {3}

{3}, {T}: Target player puts the bottom card of their library into their graveyard. If it's a creature card, you create a 2/2 black Zombie creature token.

Equipped creature has vigilance, trample, and haste. Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Equipped creature gets +4/+4. {0}: Until end of turn, Haunted Plate Mail becomes a 4/4 Spirit artifact creature that's no longer an Equipment. Activate only if you control no creatures. Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

{T}: Add {C}. {4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

When Dogged Detective enters the battlefield, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.) Whenever an opponent draws their second card each turn, you may return Dogged Detective from your graveyard to your hand.

Whenever another creature you control dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.") Whenever you sacrifice a token, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)

Defender, first strike

Defender Manor Gargoyle has indestructible as long as it has defender. {1}: Until end of turn, Manor Gargoyle loses defender and gains flying.

Flying {1}{U}: Mirror-Mad Phantasm's owner shuffles it into their library. If that player does, they reveal cards from the top of that library until a card named Mirror-Mad Phantasm is revealed. The player puts that card onto the battlefield and all other cards revealed this way into their graveyard.

Defender {3}, {T}: Target creature can't be blocked this turn.

As long as you control exactly one creature, that creature gets +3/+1 and has lifelink.