step 1 build HailStorm tower
step 2 Build boost aura
step 3 shoot a flyer , and see its HP go up
step4 when out of tower range , revert back to normal rly quick.
note , boost beam does not give this effect.
in multi player we got 220 mil hp on a few bugs.
screenshot from C2 , 33mil hp
Yeah same thing happened to me on xbox