This basically allows her to be one of the best commanders around for a good old-fashioned Creature deck
Then you get to the real payoff, Chapter III, which gives another creature you control +X/+X and trample until end of turn, where X is the number of lands you control
With there being tons of super-strong Tera-ex Pokemon, Briar can be a pivotal Supporter that can win you the game instantly if you Knock Out an ex-Pokemon while you have three Prizes left
With Drakloak and Xatu helping you draw more cards, and Tatsugiri jumping into the Active Spot early to fish out your best Supporters, this deck keeps things flowing
But it was also around the time that Hasbro / WotC was in some hot water (can you believe it?) for their brief changes to Dungeons & Dragons Open Game License, so goodwill from a crossover was likely overshadowed, at least on the internet
The strength of Staff of Compleation is it is very good late-game when you have a ton of excess mana