To me, Reuniclus looks a lot like a new age Kricketune MT. His first attack, for only one energy, lets you look at the top 5 cards of your deck, and you can rearrange them in any order. His second attack, Net Force (for only a
sychic
does 40 damage times the number of Reuniclus you have out. That attack is very interesting, and with 4 Reunclus out, you'll be hitting for 120 damage a turn. You could even run the BW Reuniclus as a supporting Pokemon to move damage counters away too. Unfortunately, right now, there isn't a lot of fast options to swarm Reuniclus, so it is more of a deck fun for league and nothing else.
90 HP is very low for a stage 2. Psychic weakness is pretty good, and the retreat cost is a bit heavy.
Overall 3/10 in modified, 1/10 in limited, and 2/10 in unlimited
In modified, this card is a bit below decent. While it can be a good attacker, and it has a good first attack, its HP is too low, and there aren't many options to swarm out Reuniclus right away compared to the days of Beedrill GE. Because of this, this card can easily out speeded and KOd, so it is generally better to play it for league then tournament. However, in our next set, we should be getting Ultra Ball, a trainer that lets you grab a Pokemon with 90 HP or less, and that card will slightly boost its speed, so it'll be a bit more usable.
In limited, this card doesn't have much a chance. It is slow to set up, HP is low for a stage 2, and there is a very low chance you'll pull out 3-4 Reuniclus to use here. Because of this, I can only see his use for Future Sight and that's about it. Otherwise, this card is kind of worth putting aside in prerelease.
In unlimited, yep, this card also won't have much of a chance. 90 HP is still way too low to deal with, yet here, there are many options to increase its speed, which is what "saves" this card from being 1/10. With many engine cards like Claydol, Uxie, etc, it can see some play, but with a lot of
sychic: Pokemon here, it'll be tough.