First, I want to get this out of the way, I do not think Freeze is inherently OP or UP at tournament standard. I just think the card has some issues.

Freeze is the only card in that game that changes effectiveness as it levels up in comparison to other cards at it's level. This causes an issue were it can only be balanced with other cards at one particular level, and will become increasingly more powerful at higher levels and under powered at lower levels.

To fix this I think it should always be a 5 second freeze. Obvousily people need some reason to upgrade the card though, so I think it should do 50 damage when placed(at Tournament Standard)(and the damage could scale when leveled). This Damage is insignificant for most cases, it will not one shot any troop(other than clones). A few cases where it would come in:

• Deal remaining damage to Wizard after he is hit by Fire Ball
• Allow X-Bow to take out each Skeleton with 1 hit
• Deal remaining damage to Minions after being hit by Princess

The other solution would be to make a Legendary, so there are far less different levels it can be upgraded to. But I have no idea how this would be done considering it is already in the game as an Epic.