Aetherworks Marvel (and similar cards) have confusing interface

Aetherworks marvel only looks at the top 4 cards of your library when activated when it should look at the top six

Start by locating the Aetherworks Marvel card implementation and the logic for its activation, then inspect how similar cards determine the number of cards looked at. Confirm the intended count from the issue and add or update relevant coverage if the repository provides it; done means the activation looks at the top six cards.

Written by the indexing model from the issue text.