Although you can use this card during your opponent's turn, if possible, it's best to use this card during your own turn so the summoned monsters can be "used up" before they have to be returned to the deck.
The tokens produced by "Mecha Phantom Beast Hamstrat" are a good way to use this card. "Waboku" can be used to protect your tokens during your opponent's turn, allowing you to use this card during your next turn to summon more "Mecha Phantom Beasts" and potentially more tokens.
During your turn, if you control 1 Level 4 "Mecha Phantom Beast" monster + 1 "Mecha Phantom Beast Token": activate this card to Tribute that one Token and Special Summon "Mecha Phantom Beast Coltwing", which will Special Summon 2 Tokens with its effect. With this, you can either use the effect of "Coltwing" to banish one opposing card or Xyz Summon a Rank 10 monster.
If the only monsters you control are two "Mecha Phantom Beast Tokens" (like from "Mecha Phantom Beast Hamstrat" that was flipped and destroyed previously), you can use this card to Summon "Mecha Phantom Beast Coltwing" and another Mecha Phantom Beast monster, thus immediately replacing the two tokens used to activate this card and potentially summoning a third token depending on which monster was summoned in tandem with Coltwing.