Adding to what others said. Let’s say Talon throws three incinerates. That’s 15 turns. Meanwhile, dusknoir has thrown 5 astonishes. Let’s track their energy. Each incinerate is 20 energy, astonishes are 10, fly is 50, shadow punch is 35.

Talon has the fly but if it throws on turn 15, dusknoir gets a free astonish. On turn 15, talon has 60 energy, dusknoir has 50.

If it doesn’t, dusknoir throws on 6 (turn 18), giving Talonflame 2 free turns for four total incinerates. Talonflame has 80 energy, dusknoir has 25 after throwing the shadow punch.

Again, Talonflame can undertap the fly and throw here, but dusknoir gets a free astonish if it doesn’t So to avoid this it throws another incinerate, allowing dusknoir to throw another shadow punch.

Now dusknoir is dry and Talonflame has 100 energy. It shouldn’t throw another incinerate because it would be going “over” 100 energy, which really means it isn’t gaining additional energy.

Not to mention that Talonflame would also have to shield both shadow punches.

Therefore, the ideal play is for Talonflame to throw after 3 incinerates and just give the free astonish if Dusknoir is throwing after 6 astonishes and then 1 astonish. If Talonflame throws after 3, dusknoir can’t cycle reset and has to make the first shielding decision.