Something to keep in mind with Trostani is that you can give any creature both deathtouch and double strike, capable of taking down practically any creature thanks to the first strike effect of double strike
It is rarely worse than Merfolk Looter and generally a good amount better
Being able to wait until the last moment keeps opponents guessing and lets you pivot based on what the table is doing
This means youre probably gonna be casting it only a couple of times each game, but the card itself is designed to make each of those plays worthwhile
Obviously, this isnt always the case, but when it comes to proxies and cards of that type, the general rule of thumb is that as long as youre upfront about them with your opponent and agree to work with them in your game, theyre fine
The in-game story of Lorcana is a bit silly but it does help explain the game mechanics and how a battle as ridiculous as Mickey Mouse and Maleficent versus Tinkerbell and Maui could ever take place