I've been playing an unholy amount of Duel Links, and i've been building T.G's in it. I decided to build T.G's in the main format, and holy ****, they are powerful.
Nearly every monster has a special summoning condition, meaning you can easily swarm a **** ton of monsters onto the board and climb into huge Synchros. Additionally, due to the T.G's all having varied types and levels, you can play f o u r generic searchers, and that's just for the T.G's ******* four.
Overall, T.G's are surprisingly ******* insane, and can perform incredibly powerful Halq combos and beat people's **** in.
also, the main core is incredibly cheap, under 30 dollars, which is really nice.
A good tech could be Fleur. Have fun.