I'm gonna go ahead and put off working out the Codex Shredder vs. Codex Shredder match. x.x

Edit: I can't believe I'm the only person who tried to turn this format's rule into an enabler.

Edit2: Okay, I think the Codex Shredders just cancel each other out. There's still a lot of looping in this match with Black Lotus, Lightning Bolt and bolted Thalia.

Edit3: Nevermind, there's definitely a case where my library is Thalia and Szat's library is Lotus on top of Bolt. In that case, the Shredders can definitely be used to do... something.

Yeah, if you ever get Thalia on the board, you win. Which means that Tevish would rather force a draw than have that happen. And the only way Tevish could win would be if he somehow got all three cards, which is impossible. Thus, he can't win, and in the situation you just described, he can force the draw (he uses his Shredder to to take Thalia, you have to respond by taking the Lotus, and then he has no mana and you have no win condition). I think we have to assume that's what happens. Unless I've missed something, it's 2-2.

Me on the play:
Lotus, Sac for , goes into enemy library
Pay for Codex Shredder
Shred Lotus into my library.
Pay for Thalia

At this point, Thalia stops him from playing anything. He can drop GV into my library, but with Thalia out, GV doesn't make enough mana for Shredder or Bolt.

When I'm on a draw, the shredders cancel and we stare at each other until the heat death of the universe, as you describe. 4-1 me.

EDIT: Just for fun...
He starts with GV/Shredder
I start with the opening as described, except I don't try to shred lotus, as he'll just shred it back.
He bolts thalia: my library is lotus, bolt, his library is thalia. It's his end step. If I shred Thalia on his end step, my library becomes Lotus, Bolt, Thalia. He can shred Lotus back to him, let's say he does that. I untap, draw Bolt, and Shred lotus so my deck is Thalia, Lotus and my hand is Bolt
He untaps, Shreds Thalia, and Draws her. I untap and draw Lotus. We stare at each other until the heat death of the universe as I have the Lotus and Bolt but don't want to give him a darn thing while he holds Thalia.

Let's check some other scenarios

he doesn't shred Lotus before I draw, I get it back in hand, with a library of Bolt, Thalia underneath. If he then shreds the bolt, I can switch it back changing my library to Thalia, Bolt. He can then untap, Shred Thalia, draw her, and we're back to that state. Or he can pass turn, let me draw bolt, and then he can't successfully steal Thalia away: I would win, so he doesn't do that. I could also decline to shred bolt back, at which point he draws it and I get Lotus/Thalia: We're back to turn 1, where if I use Lotus I lose Thalia and we enter an infinite loop

Weirder stuff. At the Thalia versus Lotus/Bolt, I could shred Lotus to him on his end step, making his library Thalia/Lotus. He could then either shred Thalia, Shred bolt to him, or shred nothing.

If he shreds bolt across, I shred Thalia on my turn and draw her. on his turn, he draws lotus, I pass, he draws bolt and zaps me for 3 making my library Lotus, Bolt. If I draw the lotus with an untapped shredder, he's through, so he shreds it over to him. I shred bolt to him, untap, and shred lotus to me on my upkeep, drawing it. he draws bolt. We are back at turn 1 except I am down 3 life so I don;t want this. If, instead, I draw bolt, I can't stop him from drawing the lotus and we draw.

If he shreds Thalia to me, I untap draw her. He untaps, and we have a Lotus shredfest that reorders his library and causes him to draw Bolt with a tapped shredder. I untap, shred Lotus to me, and we're back at turn 1

If he does nothing, I draw bolt or Thalia, his choice. Either way, we know where this goes: cruise control for draw.

So either of us can play for a draw, but neither of us can realistically win.

Me versus 5:
Me on the play, do the opening.
He drops Skerry
I draw my lotus and swing for two
He drops Agent
I swing for two. If he blocks, agent dies to first strike damage. If he doesn't, I'm up two when we both have 10-turn clocks. Win for me
When I'm on the draw, the same thing happens except I'm up one fewer swing. But I'm still up. Since Skerry enters the battlefield tapped, C-spell never comes online in time to stop Thalia taking it offline.

Me versus 6
Thalia races Inkmoth: they're both 10-turn clocks and I start swinging on my turn 2 while he can swing at the earliest on his turn 3, so even on the draw I'm at an advantage, and Inkmoth dies if it blocks.

5 Versus 6:
Neither can block the other, and they both start swinging on turn 3 with 10 turns to the kill, so whoever plays first wins. 3-3.