Which preposition to use with ultan

against Occurrences 1%

Next there arose a contention between Ultan and Declan concerning this miracle, for Ultan attributed it to Declan and Declan credited it to Ultan; and it has become a proverb since in Ireland when people hear of danger or jeopardy:"The left hand of Ultan against you (the danger)."

Which preposition to use with  ultan