I would suggest trying this disadvantage on permanents with abilities that are designed to be played before the regular casting cost would allow them to be played.
Is there any existing example for this kind of permanent in the game ? (Is Flooding one of the examples ?)
Another way to put it would be:
If a card has a powerful ability that needs to be able to be played in the early game, then it uses alternative costs to compensate for a lower casting cost.
The scramble ability is meant to hit play after only a few turns. Discord is a weapon and thus costs the player their weapon slot. This alternate cost allows Discord to have a casting cost of only 3
. The lower casting cost allows scramble to hit player earlier.
Flooding is a large effect for just 1 card. Its converted casting cost (the cost if its alternate costs were changed to casting cost) would be very high. Perhaps high enough to not be played before the game is over. The absorb cost lowers the casting cost allowing Flooding to be played midgame rather than after the game concluded.