diff --git a/app-misc/shuffle3/Manifest b/app-misc/shuffle3/Manifest
index 4ca4590..cdfde2e 100644
--- a/app-misc/shuffle3/Manifest
+++ b/app-misc/shuffle3/Manifest
@@ -2,3 +2,4 @@ DIST shuffle3-1.0.0.tar.gz 8030 BLAKE2B e1b653bcbb32cb85e469c13c751f7ef8e65119fb
 DIST shuffle3-1.0.1.tar.gz 20790 BLAKE2B 96fef9faa96de91fc53781107eb3b9ed8c72dfe8f512e2102355df79883e8cb29ebb6f077abcdf0d3d2ed7f928da15cb21a741ff9c2f948309c66e5e5a67d06a SHA512 ca41061677205421d9eb634336ec7dec38bc6f07f32b630e4af114abd2e331c086e255d106353b210c7270e9ad2315e7e8bd318d64756ad1aca872d2adfd1815
 DIST shuffle3-2.0.0.tar.gz 29547 BLAKE2B 7900396940eea1bc2ad15e2d7a79afb58c7fe2043b8e7fd07d4a9efc71bb6f0310083f703c062abaa330b9b12c7588fedaf60e52c5b29b342790218682042fcc SHA512 6429c8703e3ac3fa4bf66cd8d91c8a68053f4edf04e9f9674cfc2f4c7710688dad19c733b1feef11d044dca79ee80ee4ba714d90b19328ff595fee5364cefc35
 DIST shuffle3-2.0.1.tar.gz 129764 BLAKE2B 45ebbc22ca148dd4150570acfe5163d53f70f98adc66a89f8b4e38248c19b00c2d4d8c223e3841090a7499f80084d98e48b741a22852665feef0db549b9f6f92 SHA512 16ff2a4cd459601fbbc3933023ea59b483b7775b27df3bcfb7b50c2f2a65c8c814ac2f2120b889e9bcae518c608eb9efe4a7989887ed9c4b49bd01dc4254eddb
+DIST shuffle3-2.1.0.tar.gz 138790 BLAKE2B bd152ddc632ed1951b56299f0cc84dfadd4a184e3f1ed7ff423d43b9afa9e99d89a36d4b3e68845cb521ce6d9e9b9ae3158a8af0e89380061a2f16f56141b31b SHA512 1c0951e23ae17832d20a36bbc125acae492feae32c4579b5ff03faa0bf4ebdf5d1421c56324acf5500c4209af123735dd7b6f16d3ab70502091d6fcfabe95ddb
diff --git a/app-misc/shuffle3/metadata.xml b/app-misc/shuffle3/metadata.xml
index 5580376..a12189b 100644
--- a/app-misc/shuffle3/metadata.xml
+++ b/app-misc/shuffle3/metadata.xml
@@ -5,4 +5,9 @@
 <email>avril@flanchan.moe</email>
 <name>Flops</name>
 </maintainer>
+<use>
+<flag name="verbose">Enable debug messages in release builds. May interfere with some optimisations</flag>
+<flag name="spill">Use FS backed buffer when memory usage exeeds a threshold. Can cause massive slowdowns but prevent OOMs when unshuffling large files on systems with low available memory</flag>
+<flag name="pgo">Build with Profile Guided Optimisation</flag>
+</use>
 </pkgmetadata>
diff --git a/app-misc/shuffle3/shuffle3-2.1.0.ebuild b/app-misc/shuffle3/shuffle3-2.1.0.ebuild
new file mode 100644
index 0000000..a05348a
--- /dev/null
+++ b/app-misc/shuffle3/shuffle3-2.1.0.ebuild
@@ -0,0 +1,48 @@
+# Copyright 2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+DESCRIPTION="3 stage byte shuffler"
+HOMEPAGE=""
+SRC_URI="https://git.flanchan.moe/flanchan/shuffle3/archive/v${PV}.tar.gz -> ${P}.tar.gz"
+
+LICENSE="GPL-3+"
+SLOT="0"
+KEYWORDS="~amd64 ~x86"
+
+DEPEND=""
+RDEPEND="${DEPEND}"
+BDEPEND=""
+
+IUSE="debug pgo spill verbose"
+
+REQUIRED_USE="pgo? ( !debug )"
+
+src_unpack() {
+	default
+	mv ${PN}{,-${PV}}
+}
+
+src_compile() {
+	local FEATURE_FLAGS
+
+	FEATURE_FLAGS=""
+	use spill	&& FEATURE_FLAGS+="_FS_SPILL_BUFFER "
+	use verbose	&& FEATURE_FLAGS+="DEBUG"
+
+	if use debug; then
+		FEATURE_FLAGS="${FEATURE_FLAGS}" CFLAGS="" CXXFLAGS="" LDFLAGS="" emake debug
+		mv ${PN}{-debug,}
+	elif use pgo; then
+		FEATURE_FLAGS="${FEATURE_FLAGS}" RELEASE_CFLAGS="" RELEASE_CXXFLAGS="" RELEASE_LDFLAGS="" emake pgo
+		mv ${PN}{-pgo,}
+	else
+		FEATURE_FLAGS="${FEATURE_FLAGS}" RELEASE_CFLAGS="" RELEASE_CXXFLAGS="" RELEASE_LDFLAGS="" default
+		mv ${PN}{-release,}
+	fi
+}
+
+src_install() {
+	dobin ${PN}
+}