The Charm does 3 things, and theyre all pretty good
There are often different versions of the same Pokemon card (foil, holo), so be sure to pick a few comparables from the search results that are just like your card
Joy is a guardian who has to find and catch enemies in the first place, and since the enemies attached to the weakness are not strengthened, it is a weakness that can be easily solved as long as a reasonably strong enemy does not appear
Now, I could try to explain in my own words what that means or how they work within the rules, but that has proven dangerous in the last few weeks (did I mention that when you use a splice ability the card remains in your hand?), so instead I will refer you to the Champions of Kamigawa FAQ: Flip Cards The Champions of Kamigawa set contains ten "heroes" that are easily recognizable by their unique card frame: Akki Lavarunner -- Tok-Tok Volcano Born Budoka Gardener --Dokai, Weaver of Life Bushi Tenderfoot --Kenzo the Hardhearted Initiate of Blood --Goka the Unjust Jushi Apprentice --Tomoya the Revealer Kitsune Mystic --Autumn-Tail, Kitsune Sage Nezumi Graverobber --Nighteyes the Desecrator Nezumi Shortfang --Stabwhisker the Odious Orochi Eggwatcher --Shidako, Broodmistress Student of Elements --Tobita, Master of Winds You ignore the information on the bottom half of the card until the creature in play "flips" when certain heroic conditions are met
