Full explanation
A Mystery Reveal can turn up Wilds, and when more than one appears at the same time the game handles each on the same rule rather than treating it as a special case.
Every Wild substitutes for paying symbols to help complete combinations on the 19 lines. Any Wild that ends up part of a winning line then follows the sticky rule like other reveals: it locks in place and the grid respins around it. So multiple Wilds landing together can lock multiple positions at once, which is one of the stronger ways a respin chain builds momentum.
The honest limit is that Hacksaw has not published the fine print for every overlap (for example, exactly how a Wild interacts with a Mystery Reel resolving on the same spin). Those are genuinely edge cases and the public material does not spell them all out, so anyone giving you a definitive ruling on the rarest combinations is filling gaps with guesswork.
What you can rely on: Wilds substitute, winning Wilds stick, and several at once is good news for your chain. The deeper corner cases resolve in the game engine, not in a strategy you can act on.
What you can rely on
The dependable rules are simple: each Wild substitutes for paying symbols, and any Wild that joins a winning line turns sticky and locks for the respin. Several Wilds revealing together can lock several positions at once, which is one of the stronger ways a chain gains momentum.
The genuinely obscure overlaps, like a Wild and a Mystery Reel resolving on the same spin, are not fully spelled out in public material, and that is honest to admit. They resolve inside the game engine and are too rare to plan around. So lean on the rules that are clear and treat the corner cases as the game's business, not yours.
The comforting answer is that there are no broken corners here. Multiple Wilds in a reveal are resolved by the same payline logic that handles a single one, just with more ways to complete a line. You do not need to understand the edge cases to benefit from them. The game applies the best available outcome on its own.