{pestilence} + {high priest of penance} + anything that boosts his toughness like {honor of the pure} = 1 mana kills of any non land permanent
Add in {wall of hope} to neutralize your life loss and some other fun combos and its all downhill from there
You could just give the {High Priest of Penance} {Darksteel Plate}, then ping it with {Pestilence}, {Olivia Voldaren}, or anything else. That way you could do it any number of times per turn and not have to worry about him being a 3/3 or 1/2 or etc.
{pestilence} and {death Pitts of rath}
{Bad Moon}
{Pestilence}+ {Parallel Lives}+ {Sprouting Phytohydra}