Special Summon this card from your hand or GY in Defense Position, then you can Special Summon 1 "Drytron" monster with 2000 ATK from your GY, except "Drytron Gamma Eltanin"
For example, if your 6-mana Rhythm gets a 4/4, you can cast Rhythm for X=6 minimum the following turn thanks to harmonize
Id like to share this document I made and hear thoughts / feedback from the forum: docs.google.com TCG in Figures This Sheet is private The inspiration was An Elaborate Attempt at Print Run Estimates by @gottaketchumall
However, each of the XYZ retrains lock the player to only summoning LIGHT monsters from the Extra Deck
The drawback is that the opponent will be able to draw a card during the end phase if it is still on the board, but most players will run an XYZ monster into it to make an easy Zeus
That lets you dig through your deck and cast other key pieces that will help you convert tokens into victory