That's pretty good on its own, but the additional ability that stops opponents from casting spells on your turn means no counters and no surprises
In the casual Commander variant, you can use an oversize card as your commander - a commander starts the game face up on the table and tends to stay that way, so as above it doesn't hurt that it's oversized
So, if I cast [c]Experiment One[/c], itll have summoning sickness until my next turn
Its a defining card in Legacy and holds its own in Commander
Hiya is the reason they'll start again.
Dreamshackle Geist + Timin, Youthful Geist Timin, Youthful Geist trumps Dreamshackle Geist since it taps creatures each combat, but both spirits are exactly what a tappers deck wants: evasive threats that apply pressure to maximize the tempo of their repeated tap effects, which are incredibly efficient since they dont require additional mana