Neilan, Tempted by Sinnafex

Partner with Silken Spite (When this creature enters
the battlefield, target player may put Silken Spite into
their hand from their library, then shuffle.)
Changeling (This card is every creature type.)
Dethrone (Whenever this creature attacks the player
with the most life or tied for most life, put a +1/+1
counter on it.)
{b}{x}: Exile target creature card in a graveyard
with mana value X. Neilan becomes a copy of
that creature except it gains Changeling and
this abil