This can make it a useful card for time rules
Once the Hydra is in play your other Hydras cost four generic mana less, which is huge, especially since you can apply that four generic mana to any X cost creatures
If this card is Normal or Special Summoned: You can target 1 other Warrior monster you control with a Level
6 WHITE STONE OF THE ANCIENTS White Stone of the Ancients has double the stats (600 / 500 ) than White Stone of Legend, and it can often feel twice as useful as White Stone of Legend
I was there at the Phyrexian invasion of Dominaria when the Nine Titans gave their lives, and I was there when the planeswalkers lost their sparks, and I was there when outside IP began slowly creeping its way into the classic trading card game so it is with some confidence and experience that I say Wizards of the Coast has finally figured it out with the MTG Final Fantasy set
This may also make WotC think twice about adding any more in the future, much like Creatures with Partner