Green tends to favour big creatures, White is generally about working together with other White cards and Blue tends to favour controlling the playfield in your favour
You just need a payoff something that triggers on death or ETB, or a sac outlet like [[Phyrexian Altar]] for infinite mana
Update April 27 4:15pm CT : All BRO card prices were updated following the launch of March of the Machine
Every deck in Magic is vulnerable to different sequences of bad draws: not enough lands, not enough spells, color screw, no interaction, only finding half your combo, and so on
Obviously, Will works great with cheap ways to produce extra mana, like Rituals, but even using Will as a value engine and recasting cards like Ancestral Recall is super strong