Apply a few second "Invulnerability" to enemies that open up to Mercy.

[ShortbusGangster]

This gives you a chance to actually use the Mercy function. Many times if you are using melee you might see it but the next swing is already on its way. Same for gunfire. 

[Yuri_Doujinshi]

Ah yes, give every enemy with low health a brief invulnerability window. That won't be frustrating at all, I'm sure.

[Genitive]

9 minutes ago, Yuri_Doujinshi said:

Ah yes, give every enemy with low health a brief invulnerability window. That won't be frustrating at all, I'm sure.

I believe the OP means the same invulnerability thralls have, when they just kneel and don't attack anything. And I agree; as it is, mercy doesn't make sense.

[Kingsmount]

Not invulnerability,  but "Deathless".  They wont die until the mercy wears off whether you perform the mercy or not.   You can ignore them and they'll still die if the damage is enough to kill them,  or you can take the opportunity to perform a mercy.  Kind of like a Garuda's blood altar.

Except you can finish them off with a Mercy while in that state.   (Just like Garuda should be able to finish off blood altared enemies with her 1 if they're below 40%...)

Edited December 3, 2019 by Kingsmount

[Argenex]

The pop-up and hit a use key button to "finish" or "mercy" a random enemy, to me shows how hilariously disconnected the design is from the actual gameplay of the game;

We are slaughtering thousands if not tens of thousands, each of us, each day, ain't got time fo stabbin' one enemy with my wrist pokey stick. It's silly at best as especially now

that melee is purely spin to win where you are a whirlwind of destruction... this isn't dark souls and nor should it be.

a WARframe uses the word WAR in it, as that's what it does, makes war and makes up for a single unit combating whole armies.

If stabbing each member of an enemy once, via a cinematic was more efficient than whirlwinding thru their entire base... maybe? LOL not going to happen.

 

Invulnerability on those units will just create more bugs and slow down an already very fast-paced combat, which needs to stay fast-paced.

Edited December 4, 2019 by Argenex