Orzhov Enchantments + Lurrus companion (Standard)

POST-BAN EDIT: rip fluffy Lurrus :(

Cast auras to kill enemy creatures and draw cards with Hateful Eidolon, obtaining card advantage. Defend creatures and be evasive with Alseid of life's bounty. Win by sweeping enemy board or attacking with an all-that-glittered creature.
Against aggro and midrange, kill creatures first (even with Mogis's favor). All that glitters is basically winning against monored, as long as you have enough enchantments on the battlefield to build up a fat lifelinker. Against control and simic/dimir-flash, go aggro with All that glitters, use Mogis's favor as a buff or to kill Paradise druid, and pray not to get a Shatter the sky on your face, even though nothing's lost with reanimators and Lurrus.
If you feel like Lurrus is crucial to win a match, be careful not to get him exiled or killed while you have no reanimators. Obviously the worst threats are white/red/black exiling spells like Banishing light, Scorching dragonfire or Epic downfall. In most matchups, it's better to go safe with Lurrus on turn 4 so that you have one mana open to protect him with Alseid of life's bounty, which is useful even to counter a Brazen Borrower as well as a Bonecrusher Giant and make their adventure lose target, resulting in them going to the graveyard and not being playable as creatures.
If despark is in your hand and you are against Gyruda, doom of depths simply cast it targeting him (or thassa, deep dwelling or whatever) when it's time to break the combo.