It gives your Leader +1,000 Power that sticks during the turn, which makes it easier for you to Counter the other upcoming attacks
Ok Raging Bolt ex #208 (Pokemon Temporal Forces) Details All prices are the current market price
Doubling Season not only allows you to put out double the number of Skeleton tokens, but also doubles the number of +1/+1 counters they get on them too
Eternal Bargain I don't like what Oloro, Ageless Ascetic did to the format, but you can't deny the power and synergy of this deck, nor how he opened up a lifegain and spending mechanic in Esper
Doubling Season works exceptionally well here, doubling both the number of counters Goldvein Hydra enters play with and the number of Treasure tokens you get when it dies
Although the tokens enter the battlefield attacking, they were never declared as attacking creatures (for the purposes of abilities that trigger whenever a creature attacks, for example)