You could think about using Yami instead of Fusion Gate. That would boost Cerberus Attackpoints too :) Not just in this "special vs Pegaus" Cerberus Deck but in the general Highscore Cerberus Deck too.
it doest matter which field card you are using. it to get extra point since u can use murmur to get the card bck into hand and activate again. Its better if can get prismatic or glossy card for the field spell too
might be cause yami buffs summoned skull and umi buffs mermaid and if you need to use whatever cards are in your hand to buff up cerb and make him intimidating at the start then being forced to play and leave one of them on the field could result in you losing more lp than necessary on thus the duel