1. What is the purpose of this card? Does it bring anything special to the table?
Whimsicott - the poor man's
Celebi Prime (click here to view it).
Honestly, it's first attack (Helping Hand) is not
that bad. The problem with it is that it requires a Stage 1 pokemon, and it is an attack instead of a Poke-Power. For one {C}, you can attach any basic energy card to a pokemon on your field. There are many other worse things this could be!
Whimsicott's attack, {G} for 30 and -30 damage taken on next turn isn't terrible either. Not terrible, but still sub-par.
2. What kind of combos or decks would this card do well with?
It seems that Whimsicott was intended to be one of your first attackers - giving energy to others on your bench to power them up quickly, and possibly using Cotton Guard to stall. Unfortunately, it does cost one energy before you can start reaping the benefits, and being one turn behind with a 80 HP Stage 1 grass pokemon is not a boat that anybody wants to be in. (On a side note - you'll be a total of two turns behind a Celebi Prime, as well as having to sacrifice your turn's attack)
I can't find a combination or deck that would fit Whimsicott well. It is a large hassle for a large chance at a total net gain of 0. It might see play in a tier 3 deck if there are no other cards available to the player, but that is a scenario for the outermost fringes of the TCG.
3. Final Thoughts
Whimsicott sure tried. But, I can't find any reason to use it

.
Card Score:
2/10
Card Art:
9/10 (
ADORABLE)