"Timelines" Eras and time travel for MTG
Timelines is mainly a system to allow for dinosaurs and other prehistoric creatures to be used/allowed in a broad variety of worlds.
A ton of players from other card games like pokemon, yugioh and such make the transition to more complex games. They will grow up, and this is one carefull marketing idea.
Plus, who doesn't dig dinosaurs.
But for timelines there is an AGE card:
Age is a legendary enchantment, each player can only have one AGE in play at a time. These enchantments can still be destroyed but they all have Hexproof.. but based on the color(s) of the card your hexproof activation might be brutal.
Things like you need at least 3 creatures in play then hexproof is on.
You have to have at least 10 life, and so on.
AGE is just an enchantment that provides benefits to ALL characters.
For example:
The chosen creature type(s) are: dinosaur, fish, shark, lizard, beast, plant.
All creatures of the chosen creature type cost 1 less colorless mana to play and gain reach.
The whole point of this series is to introduce actual historical dinsaurs in a set (not just a magic name for them, the proper names like tyranosaurus rex, triceratops and so on.
Some of them will have first strike, trample, double strike and so on. Some have reach as well, mainly leaping dinosaurs.
This set should have a lot of: fight, evolution and sacrifice mechanics.
Keep it fun, a break from angels and demons for a bit, older players would still dig actual giant dinosaurs for a slugfest. The eldrazi did well for that.
Probably a lot of cards about getting out basic lands, the habitat of certain dinosaurs might be a ton of land ideas.. **** even the old old lands like bayou and taiga and such can make a comeback!
Pretty basic, there were a lot of different dinosaurs, and instead of druids or elves bringing lands into play, just have some dinos do it.
Red will of course be able to wipe out all life with that asteroid that ends it all.