Flareon week: https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-flareon-week-1-1-new-series-start-only-13-pokemon-will-be-explained & https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-flareon-week-1-2-ember-and-fs & https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-flareon-week-1-3-pros-and-cons
Golem week: https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-golem-week-2-1-similar-cp-different-demicals-losing-exeggutor-little & https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-golem-week-2-2-best-against-charizard-how-about-other-good-match-ups & https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-golem-week-2-3-1-pros-and-cons & https://pokemongo.gamepress.gg/q-a/big-19-basic-explanation-golem-week-2-3-2-mud-slap-losing-mud-shot
The previous Exeggutor explanation, the two posts before gen 2: https://pokemongo.gamepress.gg/q-a/exeggutor-explanation-part-1-basic-modified-information & https://pokemongo.gamepress.gg/q-a/exeggutor-explanation-part-2-psychic-will-soon-be-resisted
Now, it is the nightmare of Exeggutor! Exeggutor loses Confusion after the gen 2 release.
However, Exeggutor is now better for attacking purposes, learning Extrasensory and Bullet Seed. BS is decent against Omastars/Vaporeon and performs better than Exeggutor's other quick moves in these cases.
Exeggutors with Confusion or Extrasensory have the best quick moves in the Blissey matchup. In the case you can fit 3 Extrasensories, you can also fit 2 Confusions. Confusion does more damage while Extrasensory generating more energy.
[Edit]
Now we start the comparison of Blissey.
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The site shows that Exeggutor with Confusion does 83% and Extrasensory does 81% of damage, compared to Machamp with Counter/DP: http://tripledex.com/PokemonGO/Blissey
In the Zen Headbutt case, Extrasensory is superior since you can fit about 2 between Zen Headbutt and dodge. You can only fit 1 Confusion, and you will miss the dodge if you fit 2.
Next post, is still Exeggutor!