When you start to form the dome I use
(Doton: Moguragakure no Jutsu) – Earth Release: Hiding like a mole technique
Rank: C
Type: Supplementary
Range: Long
Chakra cost: 15
Damage points: N/A
Description: The user changes earth into fine sand by channeling chakra into it, allowing the user to dig through it like a mole. While underground one can sense what is happening on the surface and use the information to launch a surprise attack
To go underground (this is an official jutsu), and when underneath you I use
(Doton: Doryuso) - Earth Style: Rising Stone Spears
Rank: B
Type: Offense
Range: Short/Mid
Chakra Cost: 20
Damage Points: 40
Description: This technique lets the user condense mud or stone from the ground and shape them into spikes that will protrude from the ground to skew the target. The spikes cannot penetrate targets of greater density.
Which come from below, where the dome wouldn't cover you because you would cut yourself, and penetrate you.