Sorcerer

{u/r}: tap target creature and put a stun counter on
it activate only once per turn
Level 2: {3}{u/r}
{u/r}{u/r}: create {e}. {e}:{1}
Level 3: {3}{u}{r}
{e}{e}: the next instant you cast has split second
Level 4: {5}{u}{r}
{e}{e}{e}{e}: copy target instant or sorcery spell.
Level 5:{6}{u}{r}
{e}{e}{e}{e} counter target spell or activated ability