Greenbelt Paradox Infinite Combo (Standard)

Giving an old combo some new love!

In a dream world, Turn 4 Kill!
Turn 1: Land + Llanowar Elves
Turn 2: Land + Servant of Conduit
Turn 3: Land + Paradox Engine
Turn 4: Greenbelt Rampager = infinite mana + infinite cast

So what do we do with infinite mana + infinite cast? Choose your weapon below:
1) Walking Ballista = Death Star = Opponent Dead
2) Bontu's Monument = Infinite Life + Infinite Drain = Opponent Dead
3) Rhonas's Monument = Infinite Pump + Untap Mana Dork + Attack = Opponent Dead
4) Lifecrafter's Bestiary = Infinite Draw + find the above = Opponent Dead

MVP of the deck: Lifecrafter's Bestiary. The combos are all 4 pieces or more and involve resolving a 5 mana artifact. Luckily with a Bestiary out it's virtually impossible to run out of gas. The scry every turn is also invaluable.

Merchant's Dockhand helps to find our key pieces and Glint-Nest Crane helps to find our key artifact pieces.

Mana Ramp in Llanowar Elves, Servant of Conduit and Rishkar, Peema Renegade.

Walking Ballista is an all round player in being a combo piece, artifact, creature, removal and mana dork with Rishkar.

Longtusk Cub is an energy sink that can grow huge quickly if left unchecked. And the main combo piece itself Greenbelt Rampager can be a beatstick on its own.

Sideboard:
Aethersphere Harvester for lifelink against aggro deck and also to block problematic flyers such as glorybringer, heart of kiran, rekindling phoenix.

Against control, negate to protect our pieces and hope of ghirapur to attack and sac the turn we want to combo off.

Otherwise, we can board out some of the combo pieces to be aggressive with Verdurous Gearhulk and Longtusk Cub!

Maybeboard!
Another Turn 4 combo:
Turn 1: Land + Llanowar
Turn 2: Land + Minister of Inquiries
Turn 3: Land + Rishkar, Peema Renegade or any mana dorks
Turn 4: Land + Paradox Engine + Greenbelt Rampager = Infinite Mill = Opponent Dead