なら

if; in the case that~

ひとりで１０ 体たいぐらい 倒たおせればいけるか？
ここまで 来きたらやるしかないでしょう!
ボクたちならきっと 勝かてる！！

Can we make it if we can defeat around 10 by yourselves?
If we’ve come this far, I guess we have no choice but to do it!
If its us, we will win for sure!