OE Merrow and Other summons

I got a quick question...I OE Merrow +3 but he has not change lvl ... what +++++ OE he has to be in order for him to be lvl 79 ? and I wanna know if I OE Seraphim those his buff power increase ... right now is lvl 3 mp regen i want lvl 4 .. is that possible with OE?

cheers

+5 for 79 and +9 for 80 and the buff pets don't get more powerfull buffs, they just last longer and are harder to cancel.

OE Magnus at 48% and fail a few times then u won't OE more:P