Kudo causes all creatures to have base power and toughness 2/2.
Because Elesh Norn gives creatures your opponents control -2/-2, they will be 0/0 creatures and die as a state-based action due to having zero toughness.
This is also true for any creature that enters the battlefield under an opponent's control.

Destroy all creatures opponents control

Destroy each creature that enters the battlefield under an opponent's control

Lock

Kudo, King Among Bears

Elesh Norn, Grand Cenobite

Cast Basking Broodscale by paying {1}{G}.
When Basking Broodscale enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Basking Broodscale.
Basking Broodscale triggers, creating a 0/1 Eldrazi Spawn creature token.
When the Eldrazi Spawn enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Basking Broodscale.
Repeat from step 3.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite colorless mana

Infinite creature tokens

Infinite +1/+1 counters on a creature

Ayula, Queen Among Bears

Basking Broodscale

Cast Scurry Oak by paying {2}{G}.
When Scurry Oak enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Scurry Oak.
Scurry Oak triggers, creating a 1/1 Squirrel creature token.
When the Squirrel enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Scurry Oak.
Repeat from step 3.

Scurry Oak

Cast Herd Baloth by paying {3}{G}{G}.
When Herd Baloth enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Herd Baloth.
Herd Baloth triggers, creating a 4/4 Beast creature token.
When the Beast enters the battlefield as a Bear due to Kudo, Ayula triggers, putting two +1/+1 counters on Herd Baloth.
Repeat from step 3.

Herd Baloth

Cast Sekki by paying {5}{G}{G}{G}.
Sekki enters the battlefield as a Bear due to Kudo.
Ayula triggers, causing Sekki to fight a creature you don't control.
Sekki removes a number of +1/+1 counters from it equal to the damage it would've been dealt and creates that many 1/1 Spirit creature tokens, which are Bears due to Kudo.
When the Spirit Bear(s) enter the battlefield, Ayula triggers that many times.
If Sekki is on the battlefield, resolve an Ayula trigger, causing Sekki to fight a creature you don't control, and then repeat from step 3.
If Sekki is not on the battlefield, activate Sekki by sacrificing eight Spirits, returning it from your graveyard to the battlefield as a Bear with eight +1/+1 counters on it due to Kudo.
If Sekki entered the battlefield, Ayula triggers, causing Sekki to fight a creature you don't control.
Repeat from step 3.

Destroy all creatures opponents control whenever a creature enters the battlefield under your control

Sekki, Seasons' Guide

Cast Artificial Evolution by paying {U}, changing all instances of "Reflection" on Spirit Mirror to "Bear".
Activate Spirit Mirror by paying {0}, destroying target creature as it is a Bear due to Kudo.
Repeat step 2 as desired.
You may repeat step 2 whenever a creature enters the battlefield under an opponent's control.

Combos with "Kudo, King Among Bears"