These are alternate versions of existing cards featuring full card alternate artwork which continues to be visible behind the text
But the Green side has a lot of fun effects, like dork making, land fetching, fogging, and other fun but not powerful themes, and would enhance a given flashback slate of cards nicely
For instance: Creatures (25) 2 Llanowar Elves 2 Priest of Titania 2 Wirewood Symbiote 1 Quirion Ranger 1 Fyndhorn Elves 1 Viridian Shaman 3 Birchlore Rangers 1 Mirror Entity 4 Heritage Druid 4 Nettle Sentinel 1 Regal Force 3 Elvish Visionary Lands (16) Spells (11) In case you were wondering, yes, Ancestral Recall, Time Walk, and Timetwister had a very powerful dimension to Elves, and a playset of Skullclamps is no joke, either
Once per turn, when creatures with counters on them deal combat damage to a player, the player who controls Tidus can draw a card and proliferate (i.e., add an extra counter to creatures and permanents that already have them)