question on polymorphist's jest

hello,

so me and my brother recently played some mtg together and we ran into a disagreement. i had swung at him for 60 with a 20/20 kalonian hydra https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=420771 and a 40/40 primordial hydra https://gatherer.wizards.com/Pages/Card/Details.aspx?multiverseid=253670 . he then proceeded to play polymorphist's jest https://gatherer.wizards.com/pages/card/Details.aspx?multiverseid=433022. his thought process was that because my hydras lose all abilities. that would include 1/1 counters. my thought process was that they wouldn't lose the 1/1 counters as counters are not an ability but the hydras would lose trample as those were abilities. 

my brother decided to find what he could about rulings on jest and found this passage "Polymorphist’s Jest overwrites all previous effects that set the creatures’ base power and toughness to specific values. Any power- or toughness-setting effects that start to apply after Polymorphist’s Jest resolves will overwrite this effect.". he took that to mean that the counters wouldn't affect the hydras again until the turn was over. i went to the same rules site (the one i shared) and found this passage "Effects that modify a creature’s power and/or toughness, such as the effect of Titanic Growth, will apply to the creatures no matter when they started to take effect. The same is true for any counters that change their power and/or toughness and effects that switch power and toughness.". to me, that says the counters are still there AND still active but he read it to mean that the counters wouldn't work.

is there someone that can help me find an official ruling from a tournament or maybe some mtg arena gameplay with this interaction or has a ruling from an official? we even had my brother ask his friends (some of whom have  played since mtg started) and they were split on the issue.

The +1/+1 counters will still work.

+1/+1 counters are not an ability or effect of the creature. This is how it works when you play Kasmina's Transmutation.

It makes their base power and toughness 1/1, so it would be 1/1 and then add the +1/+1 counters. it also makes them lose all abilities, +1/+1 counters are not an ability.

i get what you're saying but i would really need an official example from say mtg arena or from an mtg tournament to get this across because kasmina's transmutation has the same text and would leave the debate in the same spot.

Here's a screenshot from a Reddit post depicting Kasmina's Transmutation (which has the same rulings) being used on an Ugin's Conjurant with six +1/+1 Counters on it. As you can see, it goes from being a 6/6 to a 7/7, as its base P/T is now 1/1 instead of 0/0, and then the Counters are applied.

This came up a lot around the time that Kasmina's Transmutation was revealed, as newer players made the mistake of thinking it would be a good counter to the Amass mechanic introduced in the same set.

+1/+1 Counters don't set P/T, they add to it. Setting would mean specifying a specific value. I'm struggling to see how the rule specifically detailing how Counters would work with Polymorphist's Jest could be misinterpreted, but I'm confident I've made way sillier mistakes in the past, so who knows.

Quote From ShadowsOfSense

Here's a screenshot from a Reddit post depicting Kasmina's Transmutation (which has the same rulings) being used on an Ugin's Conjurant with six +1/+1 Counters on it. As you can see, it goes from being a 6/6 to a 7/7, as its base P/T is now 1/1 instead of 0/0, and then the Counters are applied.

This came up a lot around the time that Kasmina's Transmutation was revealed, as newer players made the mistake of thinking it would be a good counter to the Amass mechanic introduced in the same set.

+1/+1 Counters don't set P/T, they add to it. Setting would mean specifying a specific value. I'm struggling to see how the rule specifically detailing how Counters would work with Polymorphist's Jest could be misinterpreted, but I'm confident I've made way sillier mistakes in the past, so who knows.

thanks a lot for the screenshot