Treeborn Frog can easily be used as a single tribute to summon this card. Use Soul Exchange to use one of your opponent's monster as tribute. You can also use Enemy Controller tribute control effect to use your opponent’s monster as tribute.
Berlineth the Firestorm Vassal is the direct combo synergy to Thestalos the Fire Monarch, because Berlineth’s effect when it was used to Tribute Summon, will be triggered to banish 1 card from your opponent’s hand until the End Phase (Your choice of card). Pyrorex is able to be Special Summoned when your graveyard has exactly 5 FIRE monsters.
So I got this dude twice in 5 packs (I'm F2P and reset the box after every pack cuz I own a playset of nearly any SR). Is it worth to build a deck around him? I have no Berlineth, no Treeborn Drog and only 1 Soul Exchange.
Use water vassal. Came out in age of discovery. Not exactly reliable since Escher needs oppenent to have to have two spell and trap. Could use Aurora as extreme poor mans way out since it comes back one if destroyed. Immoratal bushi is this untill non warrior is in grave.
I've loved monarchs as a card type for ages and when they got more support in the TCG I was so excited, but then they ended up too strong!
I'd like to see more of them, so far we've had Delg the dark monarch, Angmarl the fiendish monarch, and now Thestalos... if they ever give us mega monarchs we're doomed.