Obosh, the Preypiercer

So it is apparent that companions are sort of . . . good. At least half of them are playable in legacy so I want to see if we can abuse the half that aren't yet broken. Obosh seems like a likely candidate - a 6*/5 for 5 that doubles the damage output of all your spells. What is more many of Magic's best cards are odd costed. . . The cantrip cartel, OKO and Astrolab, FOW, Delver, TNN . . . . You don't have to jump through that many hoops. The only think that is hard to justify is the fact that you can't use LED, so any Obosh deck would seem to be non-optimal as long as Lurrus is legal. That said, no need to waste time and lets see how good we can get this deck in the mean time.

Now, it seems that you can easily modify a Delver or Oko deck to run Obosh on the side - unlike Jegantha, the Wellspring, which is also seeing play, you can play Obosh as a beater that's always in hand AND still play FOW. Also, although it can't win as a one card combo, like Gyruda, Doom of Depths, you can play Dark Ritual and Seething Song to accelerate this out.

So I think you can either modify an existing deck to fit it in as a beater or you can see if you can build a deck to accelerate it into play and then burn out an opponent.

Obosh - Delver

4 Delver of Secrets
2 True-Name Nemesis

2 Oko, Thief of Crowns

4 Arcum's Astrolab

4 Force of Will
4 Brainstorm
4 Ponder
4 Lightning Bolt
4 Chain Lightning
3 Spell Pierce
3 Preordain
3 Force of Negation

19 Lands

-1 Companion
Obosh, the Preypiercer

This idea is that this deck would play as a regular RUG Delver deck just without Daze. Daze is obviously important, but you exchange it for a midgame-lategame threat (a 6/5 that also doubles your burn spells, allows TNN to swing for 6 the turn it comes out, doubles your delver's power etc. You should be able to cast Obosh and perhaps even win the next turn.

Obosh - "Combo"

This will be built entirely differently. The idea here is that you want to acclerate out to Obosh as soon as possible and then chain some burn spells. The turn sequence should be something like this:

Turn 1 - Land + Discard
Turn 2 - Sol land + Seething Song OR Dark Ritual --> Obosh
Turn 3 - Land + Burn + Burn + Burn

The following should be decent for the above gameplay:

12 Lands
8 Sol Lands
4 Dark Ritual
4 Seething Song
4 Rite of Flame
4 Duress
4 Thoughtseize
4 Lightning Bolt
4 Chain Lightning
4 Lava Spike
4 Rift Bolt
4 Skewer the Critics

-1 Companion
Obosh, the Preypiercer

It should play sort of like a weird burn deck with a little bit of disruption, also with Obosh constantly in hand it can probably recover from losing gas early on, especially since Obosh can hit for 6 and doubles any burn spell that you top deck.

edit- removed fireblasts for being even CMC.