Weve already passed the critical mass of quality white creatures necessary to make a mono-colored aggro deck viable in Standard, and Shaile only adds to that roster
Our hope is this also makes things a lot clearer in terms of big game-ending cards and combos, explaining where they should show up
Song of the Dryads overwrites card type, subtypes, color, and abilities, but it doesn't touch the name or supertypes - so you'll have a legendary Forest with the same name as your Cloned legend, causing the legend rule to kick in
[c] Sanctifier en-Vec[/c] (x3): Great sideboard cards are also versatile
It stands on its own without them, providing a sac outlet, board presence, and card draw all at once, and presumably gets better with each subsequent trip to the command zone