Warren Torchmaster

You don't choose a target for Warren Torchmaster's ability at the time it triggers. Rather, a second "reflexive" ability triggers when you blight 1 this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.

Once you've announced that you're casting a spell or activating an ability, players can't take actions until you've finished doing so. Notably, opponents can't try to destroy or otherwise remove your creatures to stop you from blighting as part of paying the cost of that spell or ability.

If a creature that has +1/+1 counters on it receives enough -1/-1 counters to cause it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, effects that refer to the counters on that creature when it died will see all of those +1/+1 and -1/-1 counters.