Toxic Deluge vs Harsh Mercy in a Tribal Deck

[WWolfe]

Which do you feel is better in a tribal deck, Toxic Deluge or Harsh Mercy?

Harsh Mercy protects all your creatures (most likely) but if your opponent is running tribal or indestructible creatures, it doesn't do much.

Toxic Deluge may hit your own creatures but it hits your opponent's tribal creatures or indestructible creatures.

[Akira Foxmind]

I feel Toxic Deluge is more reliable since you can scale its size depending on the situation. Means you can aim to hit only relevant threads.

Harsh Mercy will always give your opponent the chance to decide what he wants to keep. That just doesn't feel right. 

[anjinsan]

For what purpose?

The primary point of having wipes is to wipe stuff. Therefore the biggest factor is reliability. Toxic Deluge is one of the most reliable wipes since it kills indestructible things, and for only 3 mana (of course the cost is that it struggles with very large things and/or when you’re at low health).

There is, I think, a lot of space for “value wipes”. Consider Citywide Burst, Retribution of the Meek, Winds of Rath, or indeed Harsh Mercy. These are just things that typically, when you’re running them, hit others more than they hit you. Those seem like good ways just to set other people back. However, I would be loathe only to run such cards as wipes; they don’t fill the same role.