Cheering Fanatic does not have summoning sickness.
You haven't cast an artifact spell using
Muldrotha this turn.
Steps
Declare
Cheering Fanatic as an attacker. When it triggers, choose to name the artifact.
Cast the artifact from your graveyard using
Muldrotha's ability by paying due to
Cheering Fanatic.
Displacer Kitten triggers, blinking
Muldrotha, allowing you to use its ability again this turn.
Resolve the artifact spell.
Activate
Evereth by sacrificing the artifact, putting a +1/+1 counter on
Evereth.
Repeat from step 2.
Notes
If you have a way to kill
Evereth and available, you can do so after putting a significant amount of +1/+1 counters on it to deal damage to each opponent using its second ability.
Results
Infinite +1/+1 counters on a creature.
Infinite artifact ETB.
Infinite artifact LTB.
Infinite artifact sacrifice triggers.
Infinite creature ETB.
Infinite creature LTB.
Infinite storm count.
Infinite damage.
Metadata
Bracket tag
ExhibitionBracket 1+
For any deck
1
2
3
4
5
1 · Exhibition5 · cEDH
Bracket tags are estimated from the cards and results of each combo, as a guideline rather than a strict classification.