i just was short of beating C5, but the very aggressive flying black made it too hard towards the end. before this i had killed the big grey one (the one which, when he reaches your orb, finishes the game).
the flying black not only sent waves of little black monsters, sometimes he landed on the orb and took a big amount of mana away. i hate this beast.
i then replayed C5, none of both appeared. cleared.
the shadow can become really painful if you can not kill it before the last wave is over.
I had cleared all waves on U5, 20.000 mana left. The shadow still killed me (maybe he still had 2% hp left ....)
I had 1 tower next to the orb and 5 or 6 around the map, all gems grade 8 or 9. Even with beam, bolt, barrage, curse and freeze this beast always healed itself and send one wave of black monstewrs after the other, getting harder and harder.
Then it flies around the map randomly, when you put a gem in a tower next to it - in the time the gem recharged that beat in most cases flew away ...
I always use the armour breaking gem for the shadow to kill it relatively fast. Freeze it near your towers then drop bolt/beam on the purple gems. Kill the tosser.
Two towers are usually all I build. That way I can raise the power of my killgems pretty high and I can afford as many amps as will fit. When a Shadow appears I use the strategy put forth by nichodemus; freeze, then bolt or beam. Usually one go with a g8 or better gem works a treat. If my other tower is in danger of being overwhelmed I use another freeze plus curse on the incoming monsters.
I had 1 tower next to the orb and 5 or 6 around the map, all gems grade 8 or 9. Even with beam, bolt, barrage, curse and freeze this beast always healed itself and send one wave of black monstewrs after the other, getting harder and harder.
Group the towers together at a choke point, and freeze the shadow there. If the shadow has high HP, freezing it near just one or two towers won't do.
the best thing is when i replayed U5 (with the same conditions) the beast didn't appear ,,,,,
but i still have a question about amplifiers:
i just created two red grade 4 gems for testing: in the tower: damage 70-129 plus the same gem in an amplifier: gem in the tower now damage 84-155 = +14 minimum + 26 maximum
the upgrades to range, shots per second and chain hit length are next to nothing.
so i would prefer building two towers and have 2 x damage 70-129 = + 70 minimum + 129 maximum
maybe it makes sense when you have 4 or more towers around it ?
Any gem in an adjacent Amplifier will boost the damage and range of a gem in a Tower. If they share colors, then the shared color specials will also be boosted (exception - White gems in Amplifiers do not boost White specials in Tower gems).
I do not know whether there is any optimal Amplifier gem level compared to the Tower gem level. I only know that I like to keep the Tower gem higher, but normally only by a level or two.
Before I get to the point where I can simply create a starting gem that overpowers everything, and I'm still trying to beat stages for the first time, I try to set up a 3x2 arrangement. Arranged either vertically or horizontally, that is one row of two Amplifiers, one row of two Towers, and one row of two Amplifiers. The four Amplifiers all touch both Towers, giving me twice the shots (and thus twice the firepower) of one of those two Tower gems surrounded by 4 Amplifiers.
One Tower surrounded by 8 Amplifiers works best, don't get me wrong, but that 4 Amplifier / 2 Tower setup works very well also.
