The more powerful versions of Gargos arent super hydra typal, largely because of the heavy ramp needs, but plenty of hydras slot into a fight-oriented deck
When we made the Time Spiral block many years ago, we stumbled into a phenomenon we'd never seen before
(Even Drain Life and Power Sink are in the Block)
Given were in white-black you could probably go all-in on tutors, combo pieces, discard and removal and just hope to sneak a fast win
There are actually several versions of Gandalf in the set (including Gandalf the White, whose color identity will not surprise you), and we show him at different points throughout the story by making him different colors
The ability to stem the bleeding from an aggro deck by picking off their small creatures is something that white always struggles with, making this a perfect inclusion