lol finally commenting after like ages >_< :L
okay here goes: Lava shifting, moves right to left... Okay good, but that means every slot is damaged which is harsh, but over a long time, compared to plague (as you said does not affect immortals or burrowed) is is the same but slower... this will not clear the board as some have more than 2/3 HP (the damage of lava), whereas plague means that creature pretty much dies
So not OP if this does 2 damge, I would like it to be 2 and not 3 as RoF is 3 damage and.. well.. to be different is better, also means you need 2 to kill decent creatures encourageing play....
Do not affert immortals/burrows, check good
2 damage, check good
Move right to left.... why right to left? I wuold have thought left to right, but tbh it doesn't matter (as that is upgraded), check
When you say it moves, does it only cover 1 column at a time? or 2 or what?.... also what do you consider a column as some overlap (the middle row doesn't line up with top or bottom....
Upkeep is at the end of each turn before or after it moves? so do you have to pay upkeep first go it is played?
Does it move at the end of every go or only the end of your goes... again is upkeep at the end of every go or the end of yours (not familiar with flood)... is damge dealt to cretures when lava reaches them (the turn it moves) or the start of your go? also does it damage at the end of each go or only your goes?
Sweeps once, check good
Ugraded sweeps other way, good check, however I think the cost should still be 3
for upgraded as otherwise you an kill 4 HP creatures for 5 cost whereas you need RoF (7 isn't it?) and won't kill 4 HP creatures
Keep upgraded 3
and the same except other direction ..... one card where upgrading isn't hugely important
my views, lots of questions :S :L