The Spear of Destiny (Standard)

The main strategy is to set up the dreadhorde arcanist and to give him power +1 and cast spells from your graveyard when he attacks.

This can nicely combo with Spellgorger weird : since the spells can all be cast 2 times, it is twice as much +1/+1 counters on them.

Domri's ambush is the main way to get the counters on dreadhorde arcanist in early game and you can attack and cast it a second time :
This means you do 2 dmg then 3 then attack with power 3 and toughness 5 for the total cost of 4 mana (2 for domri's ambush and 2 for the arcanist)
This can oneshot one big creature or plaswalker or kill 2 litle creatures.

In mid-late game there should be Rhythm of the wild that gives a counter so you can use Domri's ambush with better targets like fully stacked Spellgorger Weird, Sunder Shaman or even Drakuseth, Maw of Flames.

Giant Growth can give domri's ambush a litle boost against very big monsters, and shock can deal additional dmg to low lvl creatures against aggro players.

Klothys, god of destiny gets rid of their important cards in the graveyard, and the Sunder Shaman destoys artefact and enchantements (works wonders with Collision // Colossus).

Drakuseth, Maw of flames is the endgame.

Cards that can give a powerboost to Dreadhorde Arcanist (x9) :
Giant growth (until end of turn) x2, Domri's Ambush x4, Rhythm of the wild x2, Domri, Anarch of Bolas (as long as she is on the battlefield)

Cards that will create +1/+1counter on Spellgorger Weird (x19 with 14 castable twice):
Giant Growth x2, Shock x2, Season of Growth x2, Collision // Colossus x4, Domri's Ambush x4, Rhythm of the Wild x2, Thrash // Threat x2, Domri, Anarch of Bolas x1

Spells that activate the draw a card from Season of Growth (x10 all catsable twice) :
Giant growth x2, Domri'sAmbush x4, Collision // Colossus x4, Thrash // Threat x2