thys citree F

Step 1. Normal Summon Scrap Recycler or Mathematician, then activate their effect, sending Crystron Sulfefnir to the graveyard
Step 2. Activate Sulfefnir's effect in the graveyard, discarding Crystron Thystvern and special summoning itself
Step 3. Activate Sulfefnir's effect on the field, tributing itself to special summon any Crystron tuner from the deck
Step 4. Link Summon Crystron Needlefiber using the Tuner and Mathmatician/Scrap Recycler
Step 5. Using Needlefiber's effect, special summon Crystron Citree from the deck
Step 6. End your turn
During the opponent's turn
Step 7. Activate Crystron Citree's effect, Special Summon Crystron Thystvern and Synchro Summon a level 5 Synchro
Step 8. Activate Crystron Needlefiber's effect, Tributing itself to synchro summon Formula Synchron from the extra deck
Step 9. Activate Formula Synchron's effect, draw 1 card
Step 10. Activate Formula Synchron's effect, Synchro Summoning a level 7 Synchro using itself and the level 5 Synchro