Wildfire is one of those rare characters where one path really seems to be superior to the other.  That is so much so the case with Shield Slasher over Chain Champion, that I think I will reset my Dark Wildfire and take him down Shield Slasher as well.

Shield Slasher is portrayed as a trio of combo moves.  You get a bash, spin, and slam.  However, each one of these upgrades also increases the damage numbers associated with the base Traptanium Shield Bash!  It takes the already potent Shield Bash and elevates it to juggernaut numbers.

Chain Champion is unique, but it begs to question why you would want to "pull in" 5 enemies at the same time that you'll have to work hard to kill with your Shield Bash limited to 1 upgrade "Hotter Heat Shield."  The attack damage increase across this path is so small compared to Extra Chains in the base upgrade tier that you have to question if it is worth taking regardless of your tactics.  Your "wider" area is also taken back some due to the constraint of "only 5 enemies."  But again, why bring in 5 enemies the Chains won't kill on the way only to get overwhelmed by them?  It isn't an issue on easy difficulty settings, but I can imagine it wouldn't be pretty in Nightmare Mode.

It is certainly plausible that you could fend enemies off with Hotter Heat Shield, but comparing it to Shield Slasher will leave you disappointed.  Plus, when you take Shield Slasher you can still pull in 3 enemies if that is your cup of tea, and make quicker work of them.  Blazing Breath (Fire Roar) is cool, but the unidirectional line of fire and inability to move coupled with the slow attack time makes it more of a hindrance than benefit (I still think it is cool though, and really would have liked to see the Soul Gem make use of a final enhancement).

Oh, and speaking of the Soul Gem, it is unique, but not practical.  If you happen to incidentally delve into it you can unleash some significant damage, but it is really more of a "look what Wildfire CAN do" as opposed to, "I'm going to burn thru this field of enemies."  Oh, and just in case you needed more reason to take Shield Slasher, it also grants higher damage to the Soul Gem abilities.

Yep, pretty one sided.  My official endorsement for players of all skill levels is Shield Slasher.  Chain Champion isn't bad, but it is well short of what you get with Shield Slasher.