Wow.. U reborn a berserk S.Bird, Cool...
As for the Skills set, i will give up Agi+20,
Cause Agi+20 is the next round buff, your bird might not able to survive 1-hit..
Berserk Bird max HP is not very high, and your Agi dropped to 3258,
which is average stat alrd for rebirth guardian..
So if you Choose QS, Def-20 & Phy4,
Possible Scenario A is, your Bird will QS the opponent 1, (hopefully can kill it, provided u has LS infront of your bird)
Then Phy4 on the next guardian, with it's atk of 3855 plus minus enemy def-20, mostly can ohko opponent 2,
before get kill by opponent 3rd guardian.
So very unlikely your bird with avg Hp (+ the fact avg def & avg wis) can take a hit & survive it.
So the Agi Buff is kindly useless also..
Another Scenario B is, your Bird will QS the opponent 1, (hopefully can kill it, provided u has LS infront of your bird)
Then comes opponent 2nd Guardian, it's faster than your Bird,
and it OHKO you first, but u still can def-20 him,
making sure than your next phy guardian can ohko your opponent 2nd guardian.
So if me i'll give up Agi+20 for Berserk S.Bird.
If u give up the Phy4, your it could be like this,
Possible Scenario is, your Bird will QS the opponent 1, (hopefully can kill it, provided u has LS infront of your bird)
Then Scratch on the next guardian, with it's atk of 3855 plus minus enemy def-20,
We roughly assume the damage should be [(3855 x 0.85) - ((3000 - 20%) /2 (avg 5* def)) = 3302 - 1200 = avg 2102 damages]
Which i don't think can kill any reborn 5*, then after scratch first time,
your bird might not be able to scratch again to finish the opponent,
Even he does get to move twice in a row, he will get kill by opponent 3rd Guardian.
So i don't see this as a good move to remove Phy4
But i could be wrong. The above is just my own opinions.
Opt#1: As starters card, 20% AGI boost: 4800+, ATK:3712 ...It will OHKO many normal good guardian except those tankers, there is 84 guardian cant be OHKO, but with QS it may kill even more guardian. THen 2nd round if OHKO 1st card, still have chance to OHKO weaker guardian..or hurt it...
Opt#2: As starters card, DEF-20, ATK:3712 ....It will OHKO more opponent, there is 64 guardian cant be OHKO, but with QS it may kill more guardian. Then 2nd round DEF-20 wont be applied anymore, but it may still scratch 2nd opponent a bit...
IMO, in master coli usage OPT#1 is more useful due to less Ace/ALM card, so normally S Bird can OHKO more cards & also with extra AGI higher chance to OKHO 2nd card too.
But in Elite Coli, Opt#2 is worth more as it ensure S Bird to OHKO 1st opponent, then 2nd opponent just weaken it 1st. U can put another weaker QS card after S Bird like H-Nix so it can guaranteed kill opponent with QS atk....
So i my self will opt for #2.