I’m in Arena 10 as of till now, and every single person I face has either Thor or Tryko. I just wanna say I look stupid for having a freaking level 15 Ankylosaurus in battle right now, so instead of making that achievement ‘PVP Seasonal battle’, make it ‘all battles’, strike event, friendlies, campaign, I don’t care, as long as it’s a battle. I have lost over 300 trophies for 1 damn achievement and it’s starting to get ridiculous
Its hard, but I (and several others I know) were able to complete this achievement. So it’s not impossible. You just have to plan out a strategy. I’ve heard Rampage and Run into Anky works. I brought it in on a low HP draco that was still locked down.
There may be some actually impossible or borderline impossible achievements, but this ain’t it. I mean, I only started going for it this morning, and I had completed it within a few hours. I didn’t even fall below my standard trophy range. In the grand scheme of things, it’s not unreasonably hard, even in higher arenas.
I haven’t started seriously trying for it yet, but I did have a scenario in Library where it would have worked yesterday. It’s definitely doable. Also certain generous players will give you the win if they see you’re trying to get the achievement (so there is some hope for humanity after all).
If it was easy it wouldn’t be an achievement, now would it?
Nope, totally with you on this. This is ridiculous. I am glad some achievements are harder to obtain, as opposed to just giving it to us. But clearly Ludia doesn’t realize how much people CANT STAND the Arenas. Seriously, arenas are no fun! Haven’t been in awhile. Even winning feels like a relief, not enjoyable. And then they throw this junk in there. And for 50 Kentro, that’s it?
Maybe this will help you, you do have to wait for a bot battle, but at least it got the achievement done for me and I’m in Gyrosphere Depot 
https://youtu.be/IO4fdpYJmXs
If your only in avairy drop down to below 4500… lose 2 matches get the pity ai… when it gets into the swap loop just finish it with anky. Win some easy incubators on the way back up.
It’s actually quite easy. It is all about timing your swap in so it survives and then taking out a weakened opponent. I did it quite by accident.
The way I did it was wait till 3PM EST which is usually a slow amount of arena traffic, and click battle on both my phone and the wifes phone exactly the same time while within 30 trophies.
Then I switched.
Coordinate over discord.
Its hard, but possible. Did it yesterday in Gyro, when opponent went afk.
There is one impossible achievement though. There is no way to get a draw in strike tower. Its either counted as win or loss.
Also a few are impossible/near impossible for F2P
Impossible: Fire 15 darts from one drone
Near Impossible: 10 direct hits on an epic
It can be done in the tournament this weekend
I did it by rampage and run on the final hot leaving anky in play. It’s not that tough and some of these challenges should be hard to do
Confirmed did it earlier as you say , in the tourney it’s just about picking the right moment, much easier than trying to do it in the arenas 
Note: Either Anky or Anky G2 works. And Anky only needs to get 1 takedown, not win the match. I helped a friend and screwed it up as I won the match, but he still got the achievement.
What can help to make it slightly easier: plan with a friend with similar trophy levels. Can be either arena and tourney. Press battle at the same time. He was lucky as he got paired with me and drew Anky. I wasn’t. But got it during an AI battle.
wow, so any of the two ankylosaurs just have to take down 1 creature? good to know, thank you
Well now I feel like an idiot
Just tried it in current tournament, twice I finished with anky doing the last takedown and didn’t get it ?!
If the win/loss is counted the same way as in raids, I think it may only be possible if both sides use lethal wound.
Hey I done mine in tournament without any help only defeat all with Blue (29) and then change to Anky and win the last creature
Actually my thoughts on this would be to have a dinosaur that has the ability to lock in another dinosaur that is low on health and swap in your ankly! Just make sure your ankly is full health and can take out the locked in place Dino!
