Thunder Dagwon is formed from the Thunder Combination of Dag-Thunder and the Thunder Shuttle.
When the situation requires, Dag-Thunder can combine with the Thunder Shuttle to form Thunder Dagwon in order to combat tougher enemies, with Dag-Thunder combining onto the Thunder Shuttle's back.
Thunder Dagwon was first formed to combat the Pulse Seijin in Episode 36, taking the Seijin down by his own. Rai later utilized Thunder Dagwon to battle Trucker Seijin (Ep 37), witness Lian and Ark Seijin's showdown (Ep 39) and defend Dag-Base from the assault of the Walgaia Brothers (Ep 42). Thunder Dagwon will not appear from Ep 42 onwards due to Rai having to constantly take control of Dag-Base.