It has a high basic ability and a resistance effect, so it is easy to withstand even if it is summoned on the opponent's turn
If at any point you dont control a monster with that Attribute, Energizing Elements flips and the fun is over
Essentially, FF10 summons are dead people who come back to life as magical monsters, albeit temporarily
If your opponent casts Terror on one of your creatures, and you respond to it with Ancestral Recall and draw an Unsummon, you could not cast that Unsummon to save you creature before the Terror resolves, as the batch containing Terror (and Ancestral) already had started to resolve
This allows you to add two Magician Pendulum Monsters that are face-up in the extra deck (as a result of being sent from the field to the graveyard) to their hand, instantly giving you the material needed for Pendulum Summons