Pestilent Kathari

Deathtouch is a static ability.

A creature with toughness greater than 0 that’s been dealt damage by a source with deathtouch since the last time state-based actions were checked is destroyed as a state-based action. See rule 704.

Any nonzero amount of combat damage assigned to a creature by a source with deathtouch is considered to be lethal damage for the purposes of determining if a proposed combat damage assignment is valid, regardless of that creature’s toughness. See rules 510.1c–d.

The deathtouch rules function no matter what zone an object with deathtouch deals damage from.

If an object changes zones before an effect causes it to deal damage, its last known information is used to determine whether it had deathtouch.

Multiple instances of deathtouch on the same object are redundant.

Flying is an evasion ability.

A creature with flying can’t be blocked except by creatures with flying and/or reach. A creature with flying can block a creature with or without flying. (See rule 509, “Declare Blockers Step,” and rule 702.17, “Reach.”)

Multiple instances of flying on the same creature are redundant.