This is one of those cards where you wonder "What am I missing?". Getting any card from your deck is great. Getting any card from your deck when you Evolve into Roserade from hand seems promising, but then you do the math; to get one card, you're running a Stage 1 line that is an easy OHKO. If this was a Stage 1, it'd have an MD-On level of brokenness even lacking Seeker for back up; drop it when you need a card, and better your opponent hit this than finish KOing the Pokemon EX you're attacking with (assuming they can't cleverly spread damage to do both at the same time).
Level Ball can become something of a "Computer Search" when you use it to snag into this card, but you've got to have the Roselia to Evolve from first. Once you Evolve you... wish the card had a built in Devolution Spray, I guess. More cards on the pile, as it were, to try and make the combo worthwhile. If you think of it as "I already am running this", then it sounds great; again Devolution Spray becomes a Computer Search, but when you remember "oh yeah, running a OHKO-prone Stage 1 I have to set up, and it doesn't even have a good attack" you realize you may as well have run four other cards to search out two cards.
If the attack was any good, this could still have worked, but the attack is weak for a Stage 1 Pokemon, especially one where this is the only attack. Given the other Pokemon designed to combo with Devolution Spray (Bright Look Ninetales, Sporprise Amoongus, and while it works with a lot of things, Mew EX as well), this may be the weakest.