2020-08-07 : As Deepglow Skate's ability resolves, you must double each kind of counter on the permanents it targets.

2020-08-07 : To double the number of each kind of counter on a permanent, put another counter on it for each counter it already has. Effects that interact with counters being put onto permanents apply as appropriate.

2020-08-07 : You can choose no targets if you don't want to double the counters on any permanents.