Scrabble Slam

[carolcat]

must

[Ad Bot]

[Mega-Bear]

Mast.

[SailorMan]

blast

[Kill All]

cast

[Katadeus]

Cash

[Kill All]

sash

[Katadeus]

Mash

[Jake White]

Bash

[Conan]

Lash

if you could add or remove letters the next one could be slash but sadly no.

[kegeshan]

Slash

Last

[rooster767]

Fast

[popman98]

Cast

(poof poof fireballs and waterballs and every kind of ball)

[carolcat]

bast

[Mega-Bear]

Base.

As in buttery biscuit base.

[Kill All]

bare