she was "pretending" to be in danger so she could "make the Yugi she wants to appear", not knowing that she placed herself in danger of being blown up for real
When Mako duelled Yugi, he used a mixture of Krakens, sharks, jellyfish, and sea serpents as part of his deck
Master Duel gives you a generous number of gems just for completing the tutorial and logging in the first time, enough to purchase all three Special Bundles from the last tab of the in-game shop and you should purchase at least one of them
But its probably more of a fun possibility than a reliable tactic
If you do, you do so as part of the resolution of the triggered ability
Yet, there are only a few that have abilities that are powerful enough to consider them among the best tools contained in Sakakis deck