Each of these Hydras has interesting abilities but were ultimately overpowered by those in my actual top ten
Booster drafts at the store cost $15, still quite expensive for an 18 year old, but they had a new format called cube drafting
A 6/6 for six mana might seem slow, but his ability to exile creatures and then pay 1 life to gain their activated abilities is a brewing dream
If it has at least one target, and all its targets are illegal when it tries to resolve, then it won't resolve and none of its effects will happen
With Arena of the Ancients in play, any legend or Commander that wants to attack or needs to tap to activate its ability is effectively hamstrung
If you have a giant mana sink and ways to untap it, something easy to accomplish in a format like Commander, you can do this multiple times a turn and cast a ton of powerful, high-cost spells for free