Experiment Kraj and Xavier Sal do not have summoning sickness.
Devoted Druid and Seeker of Skybreak each have at least one +1/+1 counter on them.
You control at least one creature token.
Steps
Activate Experiment Kraj using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
Activate Xavier Sal's first ability by tapping it and removing a -1/-1 counter from Experiment Kraj, creating a copy of any creature token you control.
Activate Experiment Kraj using Seeker of Skybreak's ability by tapping it, untapping Xavier Sal.