the original de lo
the repaired exia is R1

the original gundam that come with the specific pilot (setsuna with Exia (basic)) usually is basic, can be identify with a bracket within the mech's name

Exia(scout MS) -> Exia(trans-am) -> R1 Exia -> R2 Exia , sadly there's no 00 gundam is the chain, so stop development and don't go for R1 exia unless you think it's cool
That is a Tornado( read as TORUNE-DO(トルネード) ) gundam for those who didn't know . And yeah the chain...

Tornado Gundam : Phoenix Zero/ RX-78 / Zeta Gundam / F-91 gundam
Phoenix Zero Gundam : Phoenix Gundam/ Shining Gundam / Wing Gundam / Gundam X
Phoenix Gundam : Tornado Gundam/ Turn-A Gundam/ Strike Gundam/ Gundam Exia

And through Shining you can get shuffle alliance, through Wing you can get whole OM MS, through Zeta you can get Ex-S and FAZZ, through exia you can get celestial being MS and so on.

Will do a OP review later, having a hard time understanding all the OP.

Using this chain should be able to complete most of mobile suit collection. There are only a few gundam you cannot get through this chain ( Destiny, Freedom, Nu-Gundam, 00 Gundam etc ), anything else is there. Don't threw away your initial gundam, they quite important for MS development. . And yeah, for destiny, freedom and justice, and easy way for it is to choose Shinn Asuka as a scout link, choosing Kira won't unlock your freedom

if u dont mind me asking, how do you guys play that SD gundam wars? on PC? with emulator?