
If you REALLY want to make things difficult for attackers (and leaving aside the Big 3), you put on Pokémon like Wobbuffet with Counter/Mirror Coat or a low level Wigglytuff with a Fairy Charge Move - low CP, High HP Pokémon that are very likely to take 2-3 battles to be kicked off the gym regardless of the motivation decay, and which will likely survive a battle long enough to get at least 1 Charged Move off that will cause damage to the Machamp Army that would be going after the Big 3 (4.maybe). Pairing and planning based on typing is a nice idea, but it doesn't particularly matter in the current Gym Defense Meta. That's just about the same strength that any Pokémon outside the Big 3 (4 if you count Slaking) have on Gym Defense. That's the strength of Steelix on Gym Defense - its ability to be placed on most any gym because people don't use it very often.

Hence why I recommended evolving a Steelix - people don't use it in Gyms very much, so the OP is going to be able to place it in just about any gym. most players who are tossing Pokémon in Gyms have Blisseys, Snorlax, Dragonites, etc. You can't do Gym Defense without getting on the Gym first. As it's vulnerable to Fighting, it won't cause any attackers to make line up changes (Machamp/Hariyama, maybe a Mewtwo with Focus Blast too) for sweeping the Gyms, but at least it looks like you're making an effort to defend the gym. So for that reason, I'd suggest evolving your Onix into a Steelix - not directly for Gym Defense, but to make it far easier for you to put a decent Pokémon on a Gym in the first place. That being said, you should have no trouble putting a Steelix into a Gym as a Defender - I honestly don't remember the last time I saw one in a Gym. (If it has Play Rough.) All other Pokémon are a distant 3rd place compared to the above 3 (4, if you count Slaking) Steelix isn't a BAD Gym Defender, but in the current Gym Meta, only 3 (maybe 4) Pokémon are actually good - Blissey, Snorlax, Chansey and maybe Slaking. Any Snorlax you get out of the current Research Rewards will be a better defender than Steelix. I will trade based on a first-come-first-served basis.The only Pokémon truly good at Gym Defense in the current Meta is Blissey, followed at a noticeable distance by Snorlax. As the game only limits 1 special trade (legendary/shiny pokemon) per day, the trade can be delay some days.I will add more shiny pokemon picture gradually, so please contact me if you do not find your pokemon yet.

I can do 1,000,000 dust trade (trade in the same day for shiny pokemon you did not own) but very limited (2/month, +$200).Please accept some hours delay in my response as we are might be in different timezones.After the purchase, please send me your FRIEND CODE via message so that I can add you as a friend.If you already caught the listed pokemon, we can trade immediately with the cost of 20,000 dust.You MUST own the pokemon in your Pokedex, otherwise, we must add friends to each other and build the friendship for 30 days to reach ULTRA FRIENDS so that the trade cost is 80,000 dust. (please check the photo of the trading cost that I attached in this listing).

