Since they are making a new L4 tower for every tower in the upcoming sequel, I had a cool idea for the new L4 Artillery
Ballista tower.
Great range (As much as a L3 archer tower)
Fires a Single huge bolt that penetrates through enemies and deals massive damage.
Extreemley slow reload.
Abilities:
Strength in Numbers: Each level get a marksman (L2 archer) to stand in the tower (Note, the marksmen only have long range) 3 Levels.
Shatter Shot: Chance to tear through armor, lowering it a level: L1: Reload 18, Chance 15% L2: Reload 16, Chance 30% L3 Reload 14, Chance 45%.
Dispell Shot: Exactly the same as shatter shot, except with magic resistance instead of armour
I couldn't decide between shatter and dispell shot, maybe they could be combined into one ability.