Addmin RFR! (this is our previous branch plus the admin and all passing tests :)  )

I'd have a single `<ul>` here instead of two.

```erb
<ul>
  <%if @character.matchups.length == 0 %>
    <li>No one yet</li>
  <%else %>
    <% @character.matchups.each do |matchup| %>
      <li><%= link_to matchup.opponent.name, matchup_path(matchup) %></li>
    <% end %>
  <% end %>
</ul>
```