The trophy will be taken to the Mend-A-Hose Jungle and presented at the end of Thursday's Super 8s game if the Tigers - 10 points clear with five rounds to go - avoid defeat.
But Trinity coach Chris Chester is hoping his own top-four aspirants can rain on their parade by condemning them to a second successive home defeat.
"There's a lot at stake for both sides," Chester said. "The League Leaders' Shield is going to be there and we've got a hell of a lot to play for as well in terms of that top four, especially with Leeds playing Saints and Salford at Wigan (on Friday).
"There are a lot of teams in and around us so it's very important that we go there and get a win.
"It's a game we're looking forward to. It's a local derby with bragging rights at stake and it's going to be a sell-out.
"Castleford are at the top of the league for a reason - they've been the most consistent team in the competition - so we know what we're up against.
"But we've seen they are beatable on their home pitch."
Castleford have won their last seven matches against their Betfred Super League neighbours but Powell is wary of the threat posed by a side that thrashed Leeds Rhinos 38-6 in their last game.
"They're playing very well," Powell said. "They looked really good against Leeds last week, we're mindful of that.
"It's a derby game and we're in front of our own fans, so it's a great opportunity for us.
"We just want to play well and enjoy the atmosphere and the pressure of it all. We should learn a lot about ourselves during this game. We're really looking forward to it.
"We've got a 10-point gap between us and second place so we're in a good position but we're not going to stress too much. Obviously we want to win this game but there's no pressure on us apart from us performing well.
"I'm confident the players will deliver our version of our very best performance level which is tough to beat."
On top of the trophy and a £100,000 cheque, a point on Thursday would earn Castleford a maiden appearance in the prestigious Dacia World Club Series and Powell, who was Super League coach of the year three years ago, admits it would rank as his greatest achievement of his coaching career.
Castleford were bottom of Super League when they sacked Australian Ian Millward 11 games into the 2012 season and had climbed just two places to 12th under interim coach Danny Orr by the time Powell answered the call a month later.
Within two years, Powell had guided the Tigers to Wembley and to within two points of top spot in Super League and they stand now on the brink of history.
"It would be right at the top," Powell said. "To see what we've built up over a number of years, to see where the club was when I came to where it is now, I get a great deal of pride from the fact that we've grown year on year as a team.
"It would be a first for us in our 91-year history and it can't be overstated how important that is.
"You still see photographs around the ground of Challenge Cup winning teams, well this is different. The competition has been in different guises but we've never finished top.
"We were close in 2014 but this would be a huge achievement for everybody concerned."
While Powell is able to choose from a full-strength squad, Wakefield have a major doubt over hooker Kyle Wood, who sustained a leg injury in the win over Leeds and with new signing Tyler Randell not expected to arrive from Australia until the day of the game, Dean Hadley and Sam Williams are likely to share the hooking duties.