time for a bit of math
currently grade 68 at wave 17 going pretty relaxed pace keeping 3-4k monsters on the gem for low lag
this is a good point to do the math since it took almost exactly 1 wave to upgrade 1 grade at this point
the obvious increase in mana cost per grade is 2.00x the previous
my mana gain increase per grade however is 1.49x
the mana gain per grade upgrade of the orange component is abuot 1.37x
the bloodhuond multiplier per hit level component is only abuot a 1.085x increase per grade level, growing at a far slower rate
these multiplied together give you the 1.49x increase per grade.
this together means each +1 gem upgrade will take 2/1.49 = 1.34x longer than the perious step
so right now at grade 68, to get a grade 80 gem for example, the waves to go from 79 to 80 would be 1.34^12 since 67-68 took 1 wave exactly.
this means 34.2 waves from 79 to 80, and i will reach grade 80 at wave 117. kinda of depressing when you think abuot going for 100.
sure hit component will go up as time goes on but only ever so slightly, maybe about 20% total throughout the entire rest of the run, but even so if we said that the incresing black part shaves off 1 wave, this still means getting grade 100 at this pace would take 34,335 waves. not very likely
this is all skills 60 too, dont think it can be improved much
based off of this, with the current strategy and using exponential growth to extrapolate (which is dangerous sometimes) im going to deem grade 100 not possible. even at 100k monsters instead of my 4k, that would still take you about 1400 waves to do
the only way around it is if you kept monsters frozen after all the waves were completed and permafroze them in place indefinately for days and days on end after all other creatures had died and the wavestones kept coming, this through very boring perserverence and 0 wiggle room for error on missing permafreeze and letting any monster move at all for days, would get you your grade 100 gem, but through conventional methods its not possible.
somewhere around the upper 80s is the realistic max
i will be trying 1 final method to get a grade 100 using a bit of a cheesy (but still about as legitimate as beating endurance with venom + blade shrine) method but im kinda hoping it works