I vote for Tortun - ponderous is such an albatross, nearly all the champs are 80+ nora with a very few exceptions. and tortun trade is nonexistent. what do ya'll think? [edit] please also give brief details about why you think the theme's weak
In terms of actually themes (not "barely-a-deck" types like FS Beasts), I'd say Jellies or SL Arthropods.
I'd trade it for slags any day, better range, better tanks, better healing and funner playstyle(by funner I mean you don't have to get hit to kill things unless you are a hanging slag)
FW spirits are pretty god awful. Mostly expensive and squishy close combat units who are made "a theme" by a gimmicky stealth ability. Filled in with expensive ranged units with not enough damage or with terrible range.
Does worst mean least fun to play or least effective in PvP? I guess you mean the latter. I feel that's aimed at me , but really FS Plants are just average. Aquatics are my pick for worst: even though they have more toys they are way, way weaker.