Ok, I know that holding that mana is counterintuitive, unless you want to do something in other players turns. You can also discuss beforehand what cards each player gonna add (we did it so we can make proxies for them). In planechase there are planes that strongly discourages players from doing some things or have severe ounishments on chaos, but that's fun too.
Regarding that 25% chance add to it that you basically have 1/3 chance to even reveal the top card. I didn't meant it to turn everyone
game plan upside down, more like a chance for
gamble that can turn the tides or be useless.
To make an example i will share some cards our playgroup added to archaeology deck by now: all 5 epic spells,
trinisphere,
winter orb,
eye of the storm,
possibility storm,
all is dust. Heck, you can even put
darksteel relic or
transcendence there so whoever picks that up will make whole table laugh.
Also as I see that you guys took some interest, so i would like to ask you if you would be so kind to check the rules, because if there is something that makes the variant unplayable then it will be a problem.