Besides just losing to an activated Mindslaver, what do you do against Control Slaver? Having played this deck for a while, and keeping it part of my testing gauntlet, I typically have Null Rod in the sideboard for this problematic matchup, as well as against Charbelcher.
Well against CS the basic plan is just to play first turn Lackey.

Barring that, I just bum rush and use Incinerators to frag Welders, because without them even with Mana Drain w/o Tinker they'll need to get up to 4 lands to cast Penti or Platy. Even with an activated Slaver, I've won some games if Food Chain wasn't resolved, because they couldn't do anything except tap me out and take a 10cc Time Walk.
I get 50/50 against Shay and I've smashed worse players on MWS easily, so take that as you will.

I really don't think CS is a problem match for my deck, Null Rod in the board would indeed be a good choice if you were expecting a lot of CS and Belcher or needed the boost. But, as far as I know, these decks aren't really played except by a few people anyways.
On top of that, I don't think a competent MWS player will consistently lose to this. Smokestacks are bad news, and Tangle Wires are possibly worse. If perchance he goes first, and goes Trinisphere, you have no chance. He just triple Time-Walked. I'm not saying other decks have much better plays against it, but FoW helps.
...? I'd go so far to say as this is one of the
best decks you could have against MWS decks. If he goes first with Trinisphere, you realize that's the exact same as against every single non-FoW packing deck right? I have 11 basics/fetches and 5 Strips, I have Welder removal which can be cast for 2 under Trinisphere and once I reach 3 mana I can cast AM, Pulverize or even just Lackey/Warchief. Hell you could even run ESG on Ancient Tomb on PURPOSE just to deal with them.
And if you do go first, the simple fact is you have one of the best shots against them as any deck does. and the board is one of the best possible. As Virtual said, "As far as having no chance. This deck plays about as much anti stax stuff as one can play without MD-ing artifact removal, or playing forces. " and even under that I
still suggest playing MD Artifact Mutations in a heavy MWS meta.