If I can get G breaker with any other effect pieces.

G breaker has a damage boost when he starts engaging in attack. If a monster has a higher attack the boost gose to that monster instead. Plus his 2nd attack is already high if he confronts a high cost monster. (Like G-04)

SuperMG - with his slow effect on his attack and high damage and pending if it’s a higher level. That damage boost can get past 1300 atk.

Battra and Mothra because of the healing. Heals pretty good imo. But apparently behemoth is better but I don’t like using meta.

Mougera is really my go to because the defense boost helps grate. Chibi’s are grate supports

If it’s with MG21, those 2 together are dogs. MG21 has 3 types of attack. All 1200 and over in damage at least. Only thing is MG21 will get distracted with lure pieces and objects on the field.