A Boy and His X: Some of the Time Shifters become friends with young boys: In the first place Flint and Getalong. Other examples are a young Auguste Rodin and Artie, a young Babe Ruth and Batterball, the young Wright brothers and Wing, a young Jean Henri Fabre and Bugsy, and a young Marco Polo and Dipper.
Brainwashed and Crazy: The vast majority of the Time Shifters at the hands of Petra, the Uglinator, and the Dark Lord.
Broken Aesop: The Time Police work under very specific guidelines — recover all the Time Shifters, no exceptions, and never disrupt the fabric of time. But reanimating two cavemen in the modern era? Allowing Bindi and Get-a-Long to roam free? No problems there. It should be noted, though, that with Petra on the loose they needed those cavemen to help with the first directive of recovering all the Time Shifters...although that still doesn't explain the Bindi and Get-a-Long part.
Eenie, Meenie, Miny Moai: Moah, the largest of the Time Shifters. When possessed by Petra, he turns into a floating Moai head that can shoot magma and cause volcanic eruptions. As the golem-like Moah-master, he can call the giant stone Moai to summon a seawall to prevent a tidal wave from washing up the island.
Enemy Mine: Used in the penultimate episode where Petra and her minions ally with Flint in fighting the Dark Lord. Only works once.
One of his minions, Uglinator, is a skull-like imp with pale yellowish teeth, dark blue horns, and bloody red eyes, complete with Sinister Scythe. His appearance is extremely menacing to the point of terror (especially his evolved form), and can also possess people just like what he did to Merlock.
The Cardians' Con form also looks like one.
Historical In-Joke: Several historic figures and events were influenced or were caused by the Time Shifters.
Irony: Merlock's only heroic moment that goes right is him defeating the evil Sara, but on pure accident. He's extremely overjoyed that he finally did something right.
Petra Fina, who attempts to possess them, has natural red eyes herself.
Remember the New Guy: The star-shaped Time Shifter Orbit, capable of encouraging people, just shows up at the start of the series finale.
Elfin was this to those with the English dub, as his episode, the Christmas Episode, didn't air until after the series finale! This was even worse in the Dutch dub, where Fox Kids had a strict policy of not airing any Christmas themed episodes. This means he just appears without any explanation at all.
Super Mode: Most of the Time Shifters' Master forms which they access on their own, usually with the help of Flint and company.
Even Nascal, Ominito, and Uglinator also have their own evolved forms (though they're described as Con forms). Nascal's has three heads a la Cerberus, Ominito turns into a giant parasitic mushroom, and Uglinator into a demon skull.
Superpowered Evil Side: When possessed by the Dark Lord (through Petra Fina or Uglinator), the Time Shifters can turn into hideous monsters called Con forms.
Super Sentai: one set of Time Shifters are basically a parody of the genre. Their combined Master Form resembles a Humongous Mecha, even!