User blog comment:Noddwyd/GSR High Vampire Attack Calculations/@comment-26896603-20150917141011/@comment-26966113-20150919071818

Speedster max atk 39999 max skill lvl

3 GSR High Vampire Boost +150% static

Starting Atk 99997.5 added + 30% for GRF and DarkX3 unit bonus - 111997.2

1st Boost 154996.125 - 173595.66

2nd Boost 240243.994 - 269073.273

3rd Boost 372378.19  - 417063.573

4th Boost 577186.195 - 646448.538

5th Boost 894638.6   - 1001995.234 (999999)

No team buff strictly necessary, though it Speeds it up a little. ;^)