Doesn't the Wizard have a push + stun ability somewhere down the line? I know such a power exists, but I don't remember where.
Elemental Maw. Which, upon reflection, is RIDICULOUS with Blood Mage.
That one is teleport, pull, prone, and dazed, so not quite what we want--dazed can still take a move action.
However, "Ice Tomb" gives a one-round stunned effect, which may be suitable for the Wile E Coyote manoeuvre described above.
Alternatively, this could be done by a team (though I realize that the whole point of this exercise is to do this with one character): have the wizard inflict blood pulse; have a martial type or paladin stun with one of the numerous melee-weapon attacks that provide stunning status; have a ranger use Great Ram Arrow or similar to knock him over the edge.