Answer: NIDORINA
Explanation: Nidorina's name has been attributed to all of these things by various fans - 'Nidoru' being the Japanese way to write 'needle', 'nido' meaning 'two times, two degrees' and some suggesting that the -rina suffix comes from 'ballerina'.
Answer: LEMONADE
Explanation: If you give the girl at the top floor of the Celadon City Dept. Store in R/B/Y a Lemonade, she will give you the Tri Attack TM.
Answer: SANDSLASH
Explanation: Sandslash's Japanese name is 'Sandopan'. The 'pan' part is obviously that makes me feel that way.
Answer: BLUEORB
Explanation: The Blue Orb is what Maxie uses in Ruby and Emerald to try to control Groudon, rather than what Archie uses to control Kyogre as one would assume from the color of the orb. Still, I guess it's because Kyogre's color angers Groudon and the other way around.
Answer: FERALIGATR
Explanation: Feraligatr appeared in an animé episode where it was entered in a sumo wrestling tournament. Makuhita and Hariyama are based on sumo wrestlers.
Answer: RAZORLEAF
Explanation: Chikorita, which is of course a starter Pokémon, learns Razor Leaf as early as level 8, which has to be seen as odd, considering its relatively high power at that stage of the game plus the high critical hit chance.
Answer: GUARDSPEC
Explanation: 'Guard Spec.' sounds like it would guard you against special attacks or something, but it actually guards you against stat reduction. Rather odd.
Answer: NETBALL
Explanation: The Net Ball works great on Bug and Water Pokémon. Most of the Water trainers don't seem anywhere near as obsessed as those Bug Catchers and Bug Maniacs, so I can't really see them jumping for joy over the existence of Net Balls. Besides, they had Lure Balls in G/S/C already.
Answer: LAVENDERTOWN
Explanation: Lavender Town seemed much more depressing back in R/B/Y than in FR/LG. The depressing monotonousness in the color and music just made it a place you wanted to avoid, don't you think?
Answer: ELIXIR
Explanation: Ethers and Elixirs (and their Max versions) are very useful items, especially when battling the Elite Four where you might run out of PP in your best attacks. However, no Pokémart sells it - not even the Dept. Stores - so you have to be content with the small supply you will find on your journey.
Answer: PECK
Explanation: 'Back in the day' should hint that I'm talking about R/B/Y here. The only damaging Flying attacks back then were Sky Attack, Fly, Drill Peck, Peck and Wing Attack. As Wing Attack's power was 35, only Moltres could learn Sky Attack naturally, and Fly was of course a HM that no Pokémon could learn naturally, that leaves Drill Peck as the most powerful one that meets the criteria and Peck/Wing Attack coming second.
Answer: HORNATTACK
Explanation: Let's see the Pokémon that can learn Horn Attack. We have the Nidoran male family, the Goldeen family, the Omanyte family and the Rhyhorn family, which have one, pretty ordinary, fairly straight horn. Fair enough. Then we have Tauros, which has two horns, Donphan and Piloswine with tusks but no actual horns, and finally Heracross with one but very creepy-looking horn. The attack animation still shows one straight horn jabbing into the opponent.
Answer: COTTONSPORE
Explanation: Well, wool and cotton are not the same thing, and cotton doesn't really have anything to do with a cactus, either.
Answer: PINSIR
Explanation: The 'purity' refers to the type of pure Bug, which only three fully evolved Pokémon have - Pinsir, Volbeat and Illumise. Volbeat and Illumise, however, were originally said to be Bug/Electric, which would be a more interesting typing in many people's opinions.
Answer: LEECHLIFE
Explanation: This is probably one of the hardest clues in this crossword. The 'sworn enemies' are the types weak to Bug, which are Psychic, Dark and Grass. Psychic has Dream Eater, Dark has Thief and Grass has Absorb/Mega Drain/Giga Drain/Leech Seed - which are the 'stealing' referred to. Bug's Leech Life also steals hit points, so that is the answer. (Covet does steal items too, but hey, it doesn't have a name like Thief.)
Answer: NANAB
Explanation: Nanab berries (the fruit of the Nanab plant) are bitter and sweet in taste and very hard in firmness. =P
Answer: LUGIA
Explanation: Okay, this is very, very far-fetched, but basically, XD is a laughing smilie, and Lugia was the star of Pokémon XD. Of course Lugia would hardly find its role in the game funny.
Answer: CHOICEBAND
Explanation: Well, isn't that basically what a Choice Band does? Make you stuck doing something that might become inconvenient very soon?
Answer: FLYGON
Explanation: As seen on the official art of it, Flygon doesn't have buglike compound eyes - it has normal eyes, and then translucent red goggle-like things around them, so one could imagine everything it sees would look red-tinted.
Answer: CROCONAW
Explanation: Uh... just look at it. You'll see what I mean.
Answer: BLUEFLUTE
Explanation: The Blue Flute cures sleep. The R/B/Y item mentioned is of course the Poké Flute - both of them being reusable 'flutes' that awaken Pokémon, rather than G/S/C's rather useless Poké Flute radio and the Awakening which is of course a one-use item.
Answer: RUSTBOROCITY
Explanation: Heh, when I was first playing through Sapphire, I noticed especially how I could walk behind the lampposts in Rustboro (unlike the previous games, where every tile was simply either something you could walk on top of or something which blocked your way).
Answer: RAPIDSPIN
Explanation: Rapid Spin gets rid of Spikes, which will hurt all Pokémon you send out except Flying-types and Pokémon with Levitate.
Answer: CLAWFOSSIL
Explanation: In Ruby and Sapphire, you are given a choice between the Claw Fossil and the Root Fossil. The Root Fossil gives you Lileep which evolves into Cradily, and Cradily happens to be one of Steven's most annoying Pokémon. In my experience, anyway.
Answer: BRICKBREAK
Explanation: This is not Rock Smash, as one would think at a quick glance, but Brick Break. What is blocking your way to victory, as in victory in battle, could be Reflect or Light Screen, those annoying barriers halving the damage you do.
Answer: AIPOM
Explanation: Ash captured an Aipom in the episode May vs. Drew! Final Battle! according to Serebii.net.